160/2002

ABB Azipod® Propulsion Systems with On-Line Measurement of Moisture in Oil

Hand-held measurements New Relative Humidity and Temperature Probes for MI70 Indicator

New technology for high accuracy measurements Vaisala DM500 Precision SAW Hygrometer

Studying the Carbon Cycles of World’s Ecosystems Contents

The AMT100 Series Ammonia Detectors were launched a year ago. They have proven President’s Column 3 their reliability in both cold and warm Ammonia environments. Demanding installation sites with different background odors and gases Vaisala Ammonia Detectors’ First Year 4 have shown that the AMT100 Ammonia Detectors have excellent ammonia selectivity, Humidity which is a key concern for many customers, for instance in the food processing industry. New Options for PHOTO COURTESY OF INGMAN Hand-Held Measurement with MI70 Indicator 6 Orion Pharma, the leading Finnish Preserving Our Antarctic Heritage - Mawson’s Huts 8 pharmaceutical company, has awarded a contract to Vaisala to support their operations. Validated Data in the Most Demanding Environments 11 Vaisala’s Humidity and Temperature Transmitters are used as part of a validated On-line Moisture Measurement of Oil 14 system that provides measurement data in Orion’s manufacturing and storage facilities New Radiation Shields 17 in Turku. The system follows strict Good Manufacturing Practice (GMP) guidelines. Moisture Assessment in Power Transformers 18

Dewpoint The historic site of Mawson’s Huts in the New Technology for Australian Antarctic Territory boasts a rich High Accuracy Measurements: DM500 22 cultural heritage but is located in very demanding environmental conditions. How to Fully Benefit from Using the DM500 24 Supporting the effort to preserve the site, Vaisala equipment is used to monitor and NWS Relies on Vaisala Instruments for study the environmental conditions. Dewpoint Measurement 26 PHOTO COURTESY OF STEVE MARTIN, STATE LIBRARY OF NSW When Direct Dewpoint Spot Vaisala supports the lifetime accuracy of the Measurement Isn’t Possible: DSS70A 28 instruments by making regular calibrations easy and affordable. The calibration reminder Accurate Monitoring of Plastic Drying Process 30 and service program offers both standard and Safe Measurements in Hazardous Areas: HMT360 Series 31 accredited calibrations, enabling customers to get the best possible performance out of their Pressure products.

CMA Invests in Accurate Vaisala Barometers 32

Easy Measurements on Site: PTU200MIK1 34

Carbon dioxide Cover photo: Studies on Carbon Cycles of the Ecosystems of the World 35 The ABB Azipod® Propulsion System is used in numerous types of vessel, such as cruise vessel Versatile Carbon Dioxide Meter for Voyager of the Seas. Photo by Gero Mylius, Professional Use: GM70 38 © INDAV Ltd, Finland. Additional features

Lifetime Measurement Accuracy 39 Editor-in-Chief: Editors: Ritva Siikamäki Bellcrest Language Services Oy Publisher: Vaisala Oyj , P.O. Printed in Finland by Vaisala in Brief Box 26 Edita Oyj, Finland FIN-00421 Helsinki – We develop, manufacture and – We focus on market segments FINLAND ISSN 1238-2388 market products and services for where we can be the world leader, environmental and industrial the preferred supplier. We put a Phone (int.): +358 9 894 91 measurements. high priority on customer satis- ONM IR EN NV T E A faction and product leadership. Telefax: L IC L +358 9 8949 2227 D A B – The purpose of these measure- We secure our competitive advan- R

E

O L ments is to provide a basis for a tage through economies of scale Internet: N better quality of life, cost sa- and scope. http://www.vaisala.com vings, protection of the environ- Design and Artwork: 441 002 ment, improved safety and bet- Edita Oyj ter performance. Printed matter

2 160/2002 President’s Column

gies are examples of this. All our ble. But when needed, we pro- products are based on our own vide recalibration. We supply R&D activities. We do not copy spare parts and upgrades for our or purchase licenses. We invest products. Our products do not 12 percent of our turnover in become obsolete, even though R&D and have committed more needs may slightly change over than 250 people to this work. the product lifecycle. The same We hold numerous patents on objective characterizes our cus- the technologies we have devel- tomer relationships. We believe oped. We also cooperate with that successful business is based the world’s leading research in- on continuing customer rela- stitutes. tionships. They can be main- Vaisala is reliable. This ap- tained only if the customers are plies both to us as a company satisfied with the products and and to our products. We want the service they get. We want to our products to operate faultless- serve our customers well, and ly even in the most demanding not to maximize our own short- conditions. Our products under- term interests. go many tests - often conducted Vaisala provides solutions. in cooperation with key cus- We do not sell our products tomers - before their through a product catalogue and market launch. Our in- leave the customer alone with house design rules have their product selection. We fa- been formed through miliarize ourselves with the ap- Vaisala’s principles experience. Concerning plications where our products measuring instruments, are used. This allows our experts accurate calibration is to assist customers in the selec- e manufacture in- of paramount importance. For tion of instruments, and in their struments for envi- this purpose we have an accred- installation, use and mainten- W ronmental measure- ited calibration measurement ance. We want to serve cus- ment – using the term “environ- standards laboratory which an- tomers well to ensure they get an ment” in its broadest sense. For swers for traceability to primary appropriate, reliable and durable us, the environment also includes standards. As a company, Vaisala solution for their needs. We are closed research premises and pro- is stable and financially sound. not out there only to obtain or- duction and process facilities. We follow strict ethical princi- ders and the customers’ money, Concerning weather measure- ples. We only promise what we which would be shortsighted ment applications we also pro- know to be feasible and we keep and foolish. vide total system solutions, while our promises. We don’t leave We have adhered to the in industrial measurement appli- our customers without support. above principles for a long time cations our focus is on supplying Vaisala’s products and cus- already. I believe that you have instruments. In all its business tomer relationships are long-last- noticed it. Vaisala is an innova- operations, Vaisala subscribes to ing. We dimension our products tive and reliable solutions a few key principles, designed to for professional use and for de- provider. G achieve satisfied customers and manding conditions. To the create mutual, lasting benefit. user, our products are invest- Vaisala is innovative. We are ments which are expected to be technology leaders in our own in service for many years. We de- field. HUMICAP®, BAROCAP® sign our instruments to require Pekka Ketonen and many other sensor technolo- recalibration as seldom as possi- President and CEO

160/2002 3 Irma Ylikangas M.Sc. (Chem. Eng.) Product Line Manager Sensor Systems Division Vaisala Helsinki Finland

Vaisala’s AMT100 Series ammonia detectors celebrate their 1st Birthday Vaisala Ammonia Detectors’ successful first year

It was one year ago that we launched the AMT100 Series Ammonia Detectors. Vaisala’s polymer thin film sensor, AMMONICAP®, has proven its reliability in both cold and warm environments (–40°C to +60°C). Demanding installation sites with different background odors and gases have shown that the AMT100 Series Detectors have excellent ammonia selectivity – thanks to the AMMONICAP® Sensor. Moreover, the low maintenance and short warm-up time of only 3 minutes have brought us many satisfied customers. This article summarizes some comments from our global customers and also gives information on AMT100 Series applications.

ne of our customers is nia Detectors for our new stor- tion warehousing industry and has gradually expanded its mar- a company called age rooms because of their per- also the number one frozen ket area to include the Baltic O KWH Freeze, who of- formance in cold temperatures food company in Japan. Mr. Rim. Apetit develops, produces fer cold storage. Their CEO, Pe- and flexible interfacing. It can be Norihiro Koishikawa, who and markets frozen foods, fish ter Lång, explains, “KWH Freeze connected directly to automa- works as team leader of the tech- products, jams and marmalades, rents refrigerated storage space tion systems or to typical gas nical section delivery team, com- all from pure, carefully selected to anyone who needs it, and also controllers.” ments on their experiences with raw materials. Apetit meets the provides internal logistics. The previous instruments: “We had requirements of clean and safe quality of our services is a high AMT100 Series entering been having problems with food production in order to priority for us as KWH Freeze is the Japanese market semiconductor type ammonia achieve sustainable develop- one of the biggest companies in We have also been successful in detectors, the main problem be- ment. Mr. Kyösti Lind, who this area in Finland. We chose introducing our AMMONI- ing false alarms caused by other works as a automation engineer Vaisala’s AMT100 Series Ammo- CAP® sensor in a very impor- gases such as hydrogen in the in the maintenance department tant industrial nation, Japan. cold storage rooms. We then at Apetit Group, points out: One of our ammonia detector tested the AMT101 and found “Apetit is Finland’s market customers, Nichirei, is a general that it does not react to other leader in frozen foods, as well as Vaisala AMT100 Ammonia processed food company based gases.” Mr. Koishikawa indicat- in jams and marmalades pro- Detectors are highly ammonia specific, which reduces costly false on storage operations. The com- ed that their alarm system is duced for retail. We have two alarms. pany is a leader in the refrigera- working well with AMT101 at production sites in Finland, one -25°C (-13°F). He also appreci- in Säkylä and another in Turku. ates the option of extra inter- When Vaisala launched their changeable probes for easy and new AMMONICAP®-based fast maintenance even in critical Ammonia Detector, we saw a situations. good opportunity to replace some old ammonia detectors in Demanding users in the problematic places.” food industry It is not difficult to find a de- Enabling the manding environment in the production of field of ammonia detection, the high-quality ice cream food industry offers excellent Within the food processing in- challenges, for example. The dustry, ice cream factories are Apetit Group markets its prod- big users of ammonia. One of ucts primarily in Finland, but Vaisala’s ammonia detector users

4 160/2002 Ammonia is a common refrigerant in cold stores and the food processing industry. Despite its many advantages, ammonia is a hazardous chemical and must always be handled in a safe manner.

food manufacturers, with an im- portant position in the dairy sec- tor. The strategy of the Group is to concentrate on milk-based products and complimentary products that apply the same production technology. The products are safe and of a high quality. Fresh Finnish milk is the most important raw material, forming the basis of production. Ingman’s main product groups are: PHOTO COURTESY OF KWH FREEZE Antero Pasanen stresses the - chilled dairy products importance of high selectivity that - liquid milk products the AMT100 Ammonia Detector - ice cream products offers. - cheese, butter and powder. “Our production facilities in Sibbo, close to Helsinki, invest- is an ice cream facility located in ed in a bigger +2°C storage the United States. This ice cream room facility in 2002. Vaisala’s plant is using ammonia as a re- Ammonia Detector was the ob- frigerant in its facility, situated in vious choice because of its high a densely populated area. As a ammonia selectivity,” comments consequence, ammonia leak de- Mr. Antero Pasanen, a technical grammed into the panel, which have not had any false alarms tection units are imperative for manager in Sibbo Factory. activate different actions within with an ammonia detector.” safety reasons. The plant has a the facility depending on the These examples of customer very elaborate control system in Ammonia detection level of ammonia that the comments are encouraging. order to monitor numerous pa- without false alarms AMT101 senses. The units have Continuous co-operation with rameters, including ammonia In food processing industry been placed outside in a docking our customers is essential during leak detection. They had a prob- there are numerous demanding station, in a machine room, in the whole lifetime of products. lem with the former ammonia measurement needs and ammo- freezers, and also in an ice cream Our aim is to continue intense sensor, a catalytic sensor, which nia detection is a very challeng- room. Mr. Smith comments: “I work in the ammonia detection was very inaccurate and required ing field for manufacturers of have been very pleased with the field and to develop even better frequent maintenance. Because measurement instruments. Con- Vaisala AMT101 Ammonia De- instruments in the future - with of the numerous odors at the ice trolled Environments Construc- tectors. This is the first time I the help of our customers. G cream facility and the tempera- tive, Inc. is a general contracting ture of the rooms, -31°C (-23°F) , firm in Tustin, California. The the catalytic sensor would not company is involved in numer- function correctly. Annoyed by ous applications, ranging from New accessory for ammonia the inaccuracies of this sensor, the pharmaceutical industry to the facility installed four Vaisala cold storage warehousing. With- detectors AMT101 Ammonia Detectors in in their organization they also aisala is launching its ice cream production rooms. specialize in control systems for V the new IP33 Box With no false alarms and all de- these applications. Controlled for AMT100 Series Am- tectors functioning correctly at Environments Constructive pur- monia Detectors. The such a cold temperature, our chased six AMT101 units in the IP33 Box has been de- customer will be replacing all summer of 2001. Mr. Mark signed for use in either catalytic sensors in the facility Smith, who works in the system outdoor or harsh in- with Vaisala AMT101 Ammonia controls and integration divi- door environments, Detectors in the future. sion, incorporated these units where the unit may Another example of an ice into a control system. In this sys- need extra protection cream manufacturer that uses tem, temperature and defrost from water. Continu- Vaisala technology is the Finnish control were also monitored in a ous cleaning and washing with sprayed water sometimes causes food industry group Ingman cold storage warehouse where extra coverage need for the ammonia detector body, especially at Foods, which is a wholly owned ammonia was used as a refriger- process sites in food processing industry. subsidiary of Ingman Group. ant. He utilized the 4-20mA sig- The detector slides into the IP33 Box and the unit is then pro- The Group has been systemati- nal from the units, which was re- tected from falling water. The box protects the unit up to a maxi- cally developed over the years to ceived on his control panel. mum raining water angle of 60 degrees. G become one of Finland’s leading There are 3 alarm levels pro-

160/2002 5 Timo Ranta-aho, Tec.Lic. Product Line Manager

Heikki Joensuu, B.Sc. (Eng.) Product Development Manager

Sensor Systems Division Vaisala Helsinki Finland

New options for hand-held measurement New Relative Humidity and Temperature Probes for MI70 Indicator

The family of new hand-held instruments for dewpoint and carbon dioxide measurements based on Vaisala MI70 Measurement Indicator was launched in 2001. A new member is now added to this product family: three new relative humidity and temperature probes in com- bination with HM70 Hand-Held Meter set further extend the selection of measurement parameters and applications.

Versatile indicator bust and easy to use. A clear ferent alternatives: English, Ger- graphic display together with an man, French, Spanish, Swedish The fully digital MI70 Measure- intuitive menu-based interface and Finnish. Graphical trends ment Indicator represents the makes it easy for the user to get enable the user to monitor the latest generation of Vaisala accustomed with the indicator. stabilization time of the meas- hand-held indicators. The indi- The language of the user inter- urement and in this way indicate cator has been designed to be ro- face can be selected from six dif- when a reliable reading can be

6 160/2002 The three new relative humidity and temperature probes, used together with the MI70 Measurement Indicator, form the HM70 family.

taken. Furthermore, a sophisti- Probe is designed for high tem- for example, the HMK15 Cali- Wide selection of cated Windows® software pro- peratures up to 180 ºC. The brator. The probes can also be measurement gram is available to transfer data probe has a 5-meter cable be- sent to a Vaisala service center parameters from the indicator to a PC, tween the small sensor head and which will provide a traceable With the new relative humidity where it can be processed further the handle, making it ideal for calibration in several humidity and temperature probes the and copied to other Windows® use in tight and difficult-to-reach points. The calibration can also MI70 Indicator is now available programs. With an analog out- areas and for the on-site calibra- be sealed making the HM70 a as three different sets, HM70 for put cable the measurement re- tion of Vaisala’s process trans- traceable humidity reference for relative humidity and tempera- sults can also be transferred to a mitters. even demanding applications. ture measurements, DM70 for chard recorder or to an external The HMP76 and HMP77 dewpoint measurements and control system. probes also have the parallel ver- Supporting the GM70 for carbon dioxide meas- The MI70 Measurement In- sions HMP76B and HMP77B, maintenance of urements. Probes for different pa- dicator automatically recognizes providing chemical purge and Vaisala’s transmitters rameters are also available indi- the connected probe and dis- sensor pre-heat options. The The HM70 effectively supports vidually, enabling the same indi- plays which parameters the chemical purge option makes the maintenance of most of cator to measure several different probe is able to measure. This the probes stable even in envir- Vaisala’s fixed relative humidity parameters. This makes the MI70 makes it easy to measure differ- onments where high concentra- transmitters. Connection cables suitable for many multiparame- ent parameters by simply chang- tions of chemicals or cleaning for both analog and digital hu- ter applications, such as green- ing the probe. Two probes can agents are present. In chemical midity transmitters are available, house monitoring, health inspec- be connected to the MI70 simul- purge, the sensor performance is enabling the comparison of tion, incubators, control meas- taneously and three measure- returned to normal by evaporat- transmitter readings with a cali- urements in building automa- ment parameters can be dis- ing the interfering chemicals brated reference probe. It is even tion, etc. With Vaisala’s stable played and logged into the indi- from the sensor polymer. Chem- possible to adjust the humidity and reliable HUMICAP®, cator memory at the same time. ical purge helps to maintain output of the transmitter in ap- DRYCAP® and CARBOCAP® Its durable and rugged struc- measurement accuracy between plication conditions without re- sensor technology, innovative de- ture, compact size and light calibrations. Sensor preheat en- moving the transmitter from the sign and easy-to-use features, the weight make the MI70 suitable ables the installation of the installation site or disconnecting MI70 and its several probes pro- for a wide variety of applica- probe in processes where high it from the monitoring or con- vides lifetime value and readings tions. humidity exists at an elevated trol system. you can trust in all conditions.G temperature. If the temperature HM70 Hand-Held of the humidity sensor during Relative Humidity and probe installation is lower than Temperature Meter that of the process, dew is easily The three new measurement formed on the sensor and it may Main Features of HM70 Series probes for relative humidity and take a long time to evaporate in temperature which, together high humidity conditions. With Measurement Indicator MI70 with the indicator, form the the sensor pre-heat function the • Graphical trend display shows stabilization HM70 family, now further ex- formation of dew can be pre- • Multi-lingual user interface tend the application base of the vented. In this way an unwanted • Programmable shortcut keys MI70 Measurement Indicator. delay in starting the actual meas- • Measurements easily reported to PC using Windows The probes are based on urements can be avoided. software Vaisala’s proven HUMICAP® The HM70 directly meas- • Two probes can be connected and measured technology. The HMP75 Hu- ures relative humidity and tem- simultaneously midity and Temperature Probe is perature. Based on the measure- • Rechargeable and alkaline battery versions available suitable for general-purpose ment of these parameters, the measurements. The HMP76 Hu- MI70 calculates dewpoint, ab- HM70 Series of Humidity and midity and Temperature Probe solute humidity and several oth- Temperature Probes enables measurements in more er humidity parameters, which • HMP75 basic humidity probe for relative humidity demanding conditions. Its long can then be displayed numeri- and temperature measurement. stainless steel shaft enables even cally or graphically and stored in • HMP76 rugged probe with a long stainless steel shaft. difficult places to be reached. the data logging memory. Preheat and Chemical Purge options available. The rugged probe structure can Calibration of the HM70 is • HMP77 probe with a cable for industrial processes up to also take rough handling better easy. The indicator provides a 180 °C. Preheat and Chemical Purge options available. G than other models. The HMP77 guided calibration procedure Humidity and Temperature which can be used together with,

160/2002 7 Ken Anderson Communications Manager Australia's Commonwealth Scientif- ic and Industrial Research Organisa- tion (CSIRO) CSIRO Built Environment Highett, Victoria Australia

Preserving our Antarctic Heritage - Mawson’s Huts

The historic site of Mawson’s Huts STATE STEVE MARTIN, OF PHOTO COURTESY NSW OF LIBRARY in the Australian Antarctic Territory is the location of one of only six surviving complexes from the era of Antarctic exploration. The site’s rich cultural heritage and demanding environmental conditions have been taken into account in the Conservation Management Plan being developed to manage the many constraints, issues and opportunities the site offers. Supporting the effort to preserve this site, CSIRO has chosen Vaisala Latitude 67 degrees south, longitude 142 degrees east, pinpoints the bleak and equipment to monitor and study inhospitable Cape Denison situated on Commonwealth Bay in the Australian Antarctic Territory. the environmental conditions.

atitude 67 degrees south, longitude 142 degrees L east, pinpoints the bleak and inhospitable Cape Denison situated on Commonwealth Bay in the Australian Antarctic Terri- tory. The windiest place on earth at sea level, Cape Denison is home to a site classified as rare in a global context and unique in Australian history. It is the lo- cation of one of only six surviv- ing complexes from the Heroic Era of Antarctic exploration… the historic site of Mawson’s Huts. Hurriedly constructed by the Australasian Antarctic Expe-

8 160/2002 dition led by Sir Douglas Maw- Action plans son in 1912, the site consists of four buildings - the Main Hut, In 1997-98, based on previous Magnetograph House, Transit heritage and condition assess- Hut and Absolute Magnetic Hut ments, AAP Mawson’s Huts - and numerous scattered arte- Foundation sent a conservation facts. Mawson remained there team to generally stabilize the for two years, directing several buildings. The team spent seven arduous journeys of exploration weeks at the site to assess the from the site and conducting sci- condition. The Main Hut and entific experiments. the Magnetograph House had Many constraints, issues and weathered their 89 years reason- opportunities have been taken ably well, maintaining intact into account in the Conserva- structures and cladding, whereas tion Management Plan that is be- the Transit Hut and the Ab- ing developed to manage the solute Magnetic Hut were subse- site’s significant cultural heritage. quently stabilized for conserva- The Mawson's Huts Historic Site and associated elements is a complex cultural landscape that illustrates, in its surviving form and setting, the tion as “standing ruins". The Historic Site - the isolation and harsh conditions encountered by the original expedition Remedying the ice abrasion members. “Home of the Blizzard” and ingress in the Main Hut has The Mawson’s Huts Historic been the most frequently pro- Site and associated elements is a posed conservation option, and temperature and relative humid- ous statistics. The steel corrosivi- complex cultural landscape that its removal appears to be a fait ity, corrosion, salt deposition ty samples indicated an atmos- illustrates, in its surviving form accompli. However, prior to a and erosion of timbers was in- pheric corrosion rate similar to and setting, the isolation and commitment to any preserva- stalled in 1999. Data-loggers or- that of suburban Melbourne and harsh conditions encountered tion strategy, it is crucial to gain ganized by the Consortium for Sydney – 12.2 microns per year. by the original expedition mem- a full understanding of the likely Heritage Collections & Their The data collected from inside bers. Foremost is the preserva- impact of action plans. Is the Environment, which consists of the Main Hut demonstrated that tion of Mawson’s Main Hut, a snow/ice inside the Hut helping CSIRO Department of Build- daily internal temperature and formidable task due to the loca- the building to be more wind-re- ing, Construction and Engineer- humidity peaks only occur when tion, environment and lack of sistant? If the ice is removed, will ing, the Australian Museum, the solar radiation is significant dur- accessibility. Cape Denison can the temperature increase around University of Canberra and the ing the Antarctic summer. The only be reached by sea in the the foundations thereby jeop- University of NSW, were posi- temperature in the Main Hut Australian summer between De- ardizing the Hut’s anchorage? tioned in the Main Hut and did not rise above 0°C, except at cember and March – a duration Will ice removal expose metal downloaded by a much-publi- the highest ceiling point, at any of one week’s sailing from Ho- surfaces to increased contact cized couple, Jim and Yvonne time during the year. Interesting- bart, Tasmania. with salt? Will it increase the hu- Claypole. ly though, the relative humidity The historic site and its midity thereby exacerbating cor- A Campbell Scientific did not fall below 80% in the buildings face an extremely de- rosion in the original bolts and CR10X monitoring system was majority of locations through- manding climate, with tempera- nails and/or increasing mould used, with eight combined out the Hut. Time of wetness tures ranging from –20°C to oc- and staining on artifacts still not Vaisala HM35A Relative Humid- (TOW), a major factor in corro- casionally over 0°C. The con- fully documented? ity Temperature Transmitters and sion study, was extrapolated stant onslaught of abrasive snow 10 surface temperature thermo- against the International Stan- and ice coupled with severe Monitoring couple sensors variously placed dard 9223 and the newly chris- winds that average a daily maxi- CSIRO has been providing ex- from floor to ceiling height and tened “King” TOW criteria de- mum of 71 kph (82 km/h) is pertise in monitoring corrosion from the outer walls to the center veloped by King and Ganther proving to be the greatest single rates at Mawson’s Hut since of the Hut to record differing from CSIRO-based work at Ter- long-term threat to the buildings. 1983. Although Antarctic tem- conditions within the building. ra Nova Bay, Antarctica, 2000. Since the 1970s various pro- peratures do curb the two most The Claypoles also exposed Research published in “Stud- posals have been made as to important factors in timber de- low-alloy copper steel coupons ies in Antarctica Help to Better how best conserve Mawson’s terioration - fungus and insects - on top of a research team build- Define the Temperature Criteri- Hut. These include covering the the common belief that a freez- ing near the Main Hut for at- on for Atmospheric Corrosion” building with a transparent ing climate will prevent bio-dete- mospheric corrosion study and by CSIRO scientists George dome, over-cladding the original rioration and corrosion, thus analysis. King and Wayne Ganther, Janet exterior timbers, dismantling the giving perfect preservation, has Hughes from the National Hut for relocation to Australia, been exposed as a myth. Revealing statistics Gallery of Australia, and Paolo and sundry other options for re- To further understand the CSIRO’s Wayne Ganther said Grigioni and Andrea Pellegrini moving the ice which has invad- deterioration processes affecting that the immense volume of da- from ENEA Italian National ed the building over its many the building structure and arte- ta collected over the 1999-2000 Antarctic Research Program, re- years of solitude. facts, equipment for monitoring period revealed some incongru- vealed that the standard ➤

160/2002 9 To further understand the deterioration processes affecting the building structure and artifacts, equipment for monitoring temperature and relative humidity, corrosion, salt deposition and erosion of timbers was installed in 1999.

benchmark ISO 9223 criterion be possible above 20% equilibri- state of the building offers some Ultimate responsibility for for estimating time of wetness is um moisture content. The sur- insulating effect. While it is ini- the conservation and manage- incorrect and needs to be re- face equilibrium moisture con- tially surprising that these ment of Mawson’s Huts Historic vised. tent in Mawson’s Hut was meas- processes are occurring, it is wor- Site rests with the Australian Utilizing King’s alternative ured as continually above 16% thy to note that it is incremental Antarctic Division as custodian criteria, the recently calculated and above 20% more than 80% over a long period of time with for the Australian Antarctic Ter- TOW data together with the de- of the time. If decay is indeed significant intermissions during ritory on behalf of the Aus- terioration of the metal artefacts possible at these temperatures winter conditions. That being tralian Government. The statu- observed on previous expedi- then there is more than enough said, even sluggish processes be- tory context for this responsibil- tions shows there is significant water available for it to proceed. come a major factor when con- ity for both cultural and natural risk to the building. Previous Despite the severe-site limi- sidering the need to preserve his- heritage conservation is provid- studies have indicated that bio- tations, the collected data has torically significant buildings for ed by the Antarctic Treaty. G deterioration of timber is said to demonstrated that the current future generations.

CSIRO has been providing expertise in monitoring corrosion rates at Mawson's Hut since 1983. Although Antarctic temperatures do retard the two most important factors in timber deterioration - fungus and insects - the CSIRO Australia common belief that the freezing climate will prevent biodeterioration and corrosion, a la 'perfect preservation', has been exposed as a myth.

CSIRO Australia is one of the world’s largest and most diverse scientific research institutions. With a staff of more than 6000, CSIRO conducts some 10% of Australia’s total R&D effort in- cluding about 12% of the R&D contracted out by industry. Globally CSIRO is active in more than 70 countries, with over 700 current or recently completed projects. Almost a third of CSIRO’s international activity is in collaboration with leading scientific organizations and firms in the USA. A fur- ther third of the international activity is with leading institu- tions and firms in Europe and Japan.

CSIRO Built Environment CSIRO Built Environment offers leading science, technology, products and services to infrastructure and built environment industries, marketing its people, technology, products and services through three core science capabilities: Thermal & Fluids Engineering, Sustainable Materials Engineering and In- frastructure Systems Engineering. G

10 160/2002 Päivi T. Laitinen B. Sc. (Env. Eng.) Application Engineer Sensor Systems Division Vaisala Helsinki Finland

Vaisala’s Humidity Measurement in the Pharmaceutical Industry Validated Data even in the Most Demanding Environments

Orion Pharma, the leading Finnish pharmaceutical company, has awarded a contract to Vaisala to support their operations. Vaisala’s HMP233 and HMP243 Humidity and Temperature Transmitters are used as part of a validated system that provides measurement data in all manufacturing and storage facilities at Orion’s premises in Turku. The system follows strict Good Manufacturing Practice (GMP) guidelines.

rion Pharma is a re- pharmaceutical products are dis- The research and develop- search and develop- covered, developed, manufac- ment and production units of O ment oriented phar- tured and marketed both for hu- Orion Pharma are situated in maceutical division of the Orion man and animal health. several locations in Finland. Ori- Group, the leading Finnish com- In Scandinavia, which is Ori- on Pharma also has a research pany specializing in healthcare on Pharma’s home territory, com- and development center in Not- products. Pharmaceutical R&D pany operations include a broad tingham, United Kingdom, at Orion Pharma focuses on four selection of human and veteri- which focuses on cardiovascular therapy areas: Central Nervous nary preparations, as well as ac- and CNS drug development. System (CNS) disorders, Cardi- tive pharmaceutical ingredients. Moreover, subsidiaries in Den- ology and Critical Care, Hor- In Finland, Orion Pharma is the mark, Germany, the UK, France monal therapies, and Respirato- leading supplier of pharmaceuti- and Sweden have medical de- ry disorders. New innovative cals with a 13% market share. partments. In the US, ➤

160/2002 11 stricter,” says Mr. Salminen from the measurement instruments Orion Pharma’s maintenance cannot be dismantled for cali- department. Orion Pharma’s bration. Vaisala could offer us validated measurement system the solution – the HMK15 Salt fulfils GMP regulations. The ob- Bath Calibrator and the HMI41 jective of the system is to pro- Indicator with HMP45 Humidi- vide proven information about ty and Temperature Probe - for the environment in Orion Phar- on-site calibration and adjust- ma at all stages of production. ment. We are extremely happy with it,” says Mr. Kollanus, Superior accuracy and Maintenance Manager of Orion easy calibration Pharma, Turku. Vaisala was the clear winner when the supplier for new instal- HMP243 for wash-down lations was decided upon, due to areas the superior performance of Moreover, Vaisala’s technology their instruments. “With Vaisala provided a solution for humidi- Mr. Pasi Kollanus (right) and Mr. Jyrki Salminen from Orion Pharma’s instruments we can always be ty measurements in spaces that maintenance department in Turku. sure the readings are true – if the are often washed. “Our produc- signal is zero, it really means ze- tion facilities are high pressure Orion Pharma collaborates in written procedures are essential ro! This is a simple thing as such, cleaned with water once or even clinical research projects with for everything that could affect but it was not so obvious with twice a day. Traditional humidi- partners. the quality of the finished prod- the other instruments we test- ty transmitters show overscale uct. There must be systems to ed,” points out Mr. Salminen. for hours after washing due to Validated system for provide documented proof that Easy calibration was also water in the sensor. Vaisala’s production control correct procedures are consis- found to be a clear advantage for HMP243 with warmed probe re- Orion Pharma’s Turku premises tently followed at each step of Vaisala. “Each measurement in- covers much faster from such have used Vaisala products for a the manufacturing process, strument is calibrated and ad- humidities and we have there- decade to measure relative hu- every time a product is made. justed both in the sensor and as fore used them to equip our midity and temperature, both “Compared to ISO9000 part of the measurement system. wash-down areas,” says Mr. indoors and outdoors. They are quality systems, GMP is much Because of the validated system, Salminen. G now building a separate, validat- ed system to measure conditions in laboratories, production, packaging and storage rooms. In The manufacturing of drugs and other pharmaceutical products is strictly controlled by GMP guidelines. addition to humidity and tem- perature, other variables are also measured. Measured conditions vary from normal room condi- tions to more demanding envir- onments. GMP – Good Manufacturing Practice The pharmaceutical industry fol- lows Good Manufacturing Prac- tice (GMP) regulations on safety and quality in manufacturing pharmaceutical preparations. According to the World Health Organization (WHO), Good Manufacturing Practice is a sys- tem for ensuring that products are consistently produced and controlled according to quality standards. GMP covers all as- pects of production from raw materials, premises and equip- ment, to the training and per- sonal hygiene of staff. Detailed,

12 160/2002 Vaisala HMP233 Humidity and Temperature Transmitter for tight places

he HMP233 is a versatile can also be set by the user. T and easy-to-use transmit- Both analog and serial out- ter for demanding industrial puts are available as well as and air conditioning applica- several other options: differ- tions. The transmitter meas- ent cable lengths, power sup- ures relative humidity and ply modules, serial interface temperature, and also outputs modules and a local display. dewpoint and wet bulb tem- The sensor head in the perature as calculated vari- HMP233 Transmitter is small ables, mixing ratio and ab- and fits into tight spaces. It solute humidity. The HMP233 can be fitted with two differ- Transmitter can be configured ent cables: one is for lower to the customer’s require- temperatures of up to +80 °C ments on the production line; and the other is for tempera- configuration and parameters tures of up to +120 °C. G

The HMP233 is suitable for duct installations, tight spaces and outdoor installations.

Vaisala HMP243 Humidity and Temperature Transmitter - designed for use in high humidity

he Vaisala HMP243 Humid- ditions can occur. The HMP243 T ity and Temperature Trans- Transmitter is fully config- mitter is specially designed for urable and outputs dewpoint, reliable and fast dewpoint relative humidity, ppmv and measurement at high humidi- temperature. ties and/or rapidly changing temperatures, where condens- Excellent Performance ing water vapor has been a under High Humidity problem. The HMP243 incorpo- Vaisala’s unique warmed rates Vaisala’s advanced HUMI- probe provides fast and reli- CAP® technology and a able dewpoint measurements warmed probe head to guaran- in environments where hu- tee accurate and reliable dew- midity almost reaches satura- point measurement even in tion. The sensor also recovers condensing environments. very fast from condensation in The HMP243 works well extreme conditions. As the both at lower humidities and probe is warmed, the humidi- in saturating conditions. In ad- ty level inside the head stays dition to industrial applica- below the ambient. With ac- The HMP243 can be tions it is suitable for use in curate temperature measure- equipped with an outdoor/meteorological appli- ment the dewpoint of the am- optional temperature cations where sudden temper- bient environment can be pre- sensor for ambient ature changes and windy con- cisely calculated. G temperature and relative humidity measurement.

160/2002 13 Päivi T. Laitinen B. Sc. (Env. Eng.) Application Engineer Sensor Systems Division Vaisala Helsinki Finland

Marine is a lead- state-of-the art electric propul- first azimuthing podded propul- ABB ing global elec- sion drives for luxury cruise ves- sion system on the market, at the trotechnical partner with the ma- sels, ro-ro vessels, tankers and beginning of the 1990s. The Azi- rine industry. ABB supplies offshore and special purpose pod propulsion system com- power plants and electric vessels for more than half a cen- bines the advantages of various propulsion systems - including tury. conventional propulsion sys- azimuthing electric propulsion, tems available today. The ® total automation systems and a Azipod Propulsion propulsion system provides the wide range of other electrotech- System – the world’s major benefits of excellent dy- nical products and drive sys- leading propulsion namic performance and maneu- tems. ABB Marine has provided system vering characteristics, hydrody- the world’s shipbuilders with ABB introduced Azipod, the namic efficiency resulting in

HMP228 Moisture and Temperature Transmitter for Oil On-line Measurement of Oil Gives up-to-date Information for Operators

The Propulsion Unit of ABB Marine and Turbocharging relies on Vaisala to measure the moisture in lubrication oil on-line. The Vaisala HMP228 Moisture and Temperature Transmitter for Oil is a standard feature in the ABB Azipod® propulsion system. The HMP228 provides fast, reliable and accurate measurements of moisture in oil in the cir- culation lubrication system of under-water propulsion motors.

14 160/2002 shorter harbor times, reduced fu- The ABB Azipod® propulsion el consumption and safer opera- unit. tion even in harsh weather, re- stricted passages and offshore environments. The Azipod system is an azi- muthing electric propulsion drive with a propulsion motor installed inside a submerged azi- muthing (unlimited 360 degrees) pod, coupled directly to an ex- tremely short propeller shaft. The variable speed electric been installed in over twenty and other problems. Measuring ship’s machine room, where the (AC/AC) drive produces Azipod systems. It is a standard and controlling the moisture in HMP228 unit is located. The smooth torque over the entire feature in new propulsion units lubrication systems is essential purpose of on-line detection of speed range, including zero and retrofittings are also being to avoid costly failures. Careful moisture in oil is to monitor oil speed. ABB designs and manu- done on old units. “The on-line monitoring of the moisture in quality and to secure the proper factures Azipod propulsion detection of moisture in oil with oil within lubrication systems lubrication quality. “The units for all marine propulsion HMP228 has raised a lot of in- helps to plan servicing and pre- amount of oil in the Azipod applications, with units available terest and customers are really vent unscheduled downtime, propulsion system is rather small with powers of up to 25 MW. willing to have the HMP228 thus potentially cutting main- -- only around 200 liters -- com- units in their ships, even as retro- tenance costs substantially. On- pared to traditional propulsion Over 10 years marine fittings,” says Mrs Lundell, Pro- line detection is especially im- systems that have up to 4000 experience duction Engineer of ABB Ma- portant in applications with a liters of lubrication oil,” explains Azipod was first conceived in rine and Turbocharging, Propul- risk of water contamination, for Mrs Lundell. “With such a small 1987. After several years of re- sion Units. example marine applications. amount of oil even a small search and development, the In the Azipod propulsion amount of water will reduce lu- world’s first Azipod® propul- On-line measurement system the electric propulsion brication quality, therefore, the sion system (1 x 1500 kW) was helps operators motors are located under water. moisture in the oil in the lubrica- delivered in 1990 to the service monitor oil quality Each motor has two bearings, a tion system must not exceed cer- vessel “Seili”. This was followed Water contamination reduces propeller bearing and a thrust tain limits. The HMP228 issues a by the first tanker application the performance of oil, increas- bearing. The lubrication system warning immediately something “Uikku” (1 x 11 400 kW) in ing the risk of corrosion, over- circulates oil from bearings in has happened so that the oil can 1993, the first icebreaker appli- heating, machine malfunction the propulsion unit to inside the be changed or purified.” ➤ cation “Röthelstein” (2 x 560 kW) in 1994, and the first cruise vessel application “Elation” (2 x 14 000 kW) in 1998. By 2002, 76 Azipod units had been delivered to a total of 36 ships, with 11 de- livered to ice breaker applica- tions. Azipod units now have more than 472,000 cumulative operating hours in the world’s seas. Vaisala HMP228 Moisture and Temperature Transmitters for Oil are being installed in Azi- pod propulsion systems to meas- ure on-line the moisture in the oil in circulation lubrication. Each ship has from one to three propulsion units and each propulsion unit has its own Mrs Susanna Lundell, Production HMP228 to control oil. Engineer of ABB Marine and HMP228 units have already Turbocharging, Propulsion Units.

160/2002 15 HMP228 provides flexible and easy measurement The first system ABB used to de- tect moisture in oil was an opti- cal measurement system. “Opti- cal measurement was expensive and difficult to assemble,” re- The on-line detection of moisture in marks Mrs Lundell. “After test- oil is especially important in those ing the HMP228 and finding it applications with a risk of water fast, reliable and accurate we de- contamination, such as marine cided to change to it for on-line applications. moisture detection. Above all, the HMP228 is easy to assemble and use: just fix the ball valve and connect the cables and the HMP228 is ready to go!” Oil type, age and temperature irrelevant Measurement with the HMP228 is independent of oil type, age and temperature. The HMP228 Transmitter measures water in oil in terms of water activity (aw). The water activity measure- ment indicates directly whether A HMP228 unit installed in a there is a risk of free water for- ship’s machine room. Installation is mation. With a relative scale easy and convenient to perform from 0 (no water present) to 1 through a ball valve. (oil is saturated with water) it gives a reliable indication of how close the saturation point is. Wa- ter in its free form has a water ac- The Vaisala HMP228 allows tivity of 1. As the solubility of the on-line moisture measurement of oil water in oil increases with rising temperature, the saturation he HMP228 Moisture and Temperature The HMP228 incorporates Vaisala’s HUMI- point of oil pulls further away. T Transmitter for Oil offers fast, reliable and CAP® capacitive thin film polymer sensor, Thus water activity decreases accurate on-line detection of moisture in oil. known for its accuracy, reliability and long- with rising temperature. The transmitter is especially designed for lubri- term stability. G According to Mrs Lundell, cation and hydraulic oil systems, such as paper using water activity as a unit is machines, diesel engines and power plants. new in the marine industry: “We The Vaisala HMP228 Transmitter measures have become accustomed in this water activity and temperature in oil. The wa- field to seeing water saturation ter activity (aw) measurement offers several ad- expressed as ppm. ABB has there- vantages compared to the traditional ppm- fore had a conversion diagram measurement. The HMP228 provides reliable from aw to ppm made by the information on how close the oil is to its satu- VTT Technical Research Centre ration point. Oil-specific calibration is not nec- of Finland. Water activity has cer- essary, as water activity is not affected by the tain advantages in its independ- type or age of the oil. Moreover, the transmit- ency of oil type, age and tempera- ter can be ordered with a ball valve set, allow- ture, but as long as our customers ing the probe to be installed and removed for in the marine industry are more calibration without needing to drain the oil The HMP228 controls the lubrication oil of a familiar with ppm than aw values system. propulsion unit’s bearings. we will use them too.” G

16 160/2002 The new radiation shields are used in outdoor installations to protect relative humidity and temperature measurement instruments from rain and sun radiation. New Radiation Shield Models DTR502B and DTR503A

aisala has launched new The Vaisala DTR502B Radi- The DTR503A Radiation Shield radiation shield models ation Shield is a naturally venti- offers an accessory for V which are available for lated 9-plate radiation shield HMP45A/D Humidity and vertical pole, horizontal beam or complete with accessories to al- Temperature Probe mounting. flat surface, such as wall, installa- low easy installation of the sen- In both models, the plates of tion. The new radiation shield sor heads of HMP233 and the shields are made of a special models are easy to install, main- HMP237 Humidity and Tem- material that offers excellent tenance free, and available sepa- perature Transmitters into the thermal characteristics and UV rately as an additional accessory shield. In addition to the sensor stabilized construction. For max- for the humidity instruments, to head accessories, the mechanics imum protection, the outer sur- be integrated, for example, into for pole installation (i.e. vertical faces are white to reflect radia- HVAC application ventilation installation) is included. tion and the insides are black to systems or a wide variety of The Vaisala DTR503A Radi- absorb accumulated heat thus weather stations and observing ation Shield is a naturally venti- eliminating the possible warm- systems. The shields protect lated 12-plate radiation shield ing inside the shield and result- measurement instruments from included with a similar vertical ing in very good measurement scattered and direct solar radia- pole, horizontal beam or flat results in outdoor applications. tion and rain, ensuring reliable surface installation set to that of G measurement data. the DTR502B Radiation Shield.

160/2002 17 V. G. Davydov Monash University Australia

O. Roizman IntellPower Australia

Moisture assessment in power transformers The molecular flow of mois- ture is practically negligible. The main mechanism of water pene- tration is the viscous flow of wet Lessons Learned air through “poor sealing”, i.e. through the sealing points of bushings, the explosion vent and the cooling circulation loop The need to know the water content of paper accurately under etc., due to the pressure gradi- all operating conditions is essential for the safe operation of ent. Large amounts of rainwater can be pumped into the trans- transformers. To improve existing methods of determining the former in a very short period of water content of paper, a concept of “water-in-paper activity” time (just a few hours) if there is has been developed. The water solubility parameter is of improper sealing and a rapid 1 paramount importance for the accurate evaluation of water drop in pressure . content. A stand-alone software application, the Transformer Methods and Moisture Monitor (TMM), is recommended for moisture instrumentation for moisture measurement assessment. The development of a new classification procedure The term “moisture” in the provides a means of ranking dry and wet transformers. transformer industry is com- monly used to indicate water which is absorbed in the paper or dissolved in the oil. Occasion- ally, the terms “water” or “water ater in transformers get value of 0.5%. Excessive content” are used as an alterna- appears as an un- residual moisture of 2-4% can re- tive way to describe the same W wanted substance, main in some thick insulation substance. decreasing insulation breakdown components, particularly plas- Water in transformers can be strength and shortening trans- tics1. During service, this mois- found in different parts of the former life dramatically. High ture gradually seeps into the oil, insulation system. It can accu- water content in paper may re- increasing the water content in mulate in solid insulation, be sult in bubbling, the formation the thin insulation structure1. dissolved in oil, or be found in of free water and an increased Atmospheric water is the the form of liquid water at the risk of dielectric breakdown. Wa- main source of transformer con- core or bottom of a transformer. ter also causes accelerated paper tamination. Three mechanisms Depending on the media, differ- aging, corrosion of core/tank are acting here: the absorption ent methods and instrumenta- and progressive consumption of of water from the direct expo- tion are used for moisture meas- oil additives. sure of the insulation to the air urement. For example, to evalu- Water contamination in (installation and repair works), ate water content in oil, polymer transformers comes from three the ingress of moisture in the relative humidity/relative satura- main sources: residual moisture form of molecular (Knudsen) tion sensors are frequently used. in the “thick structure elements”, flow due to the difference in the By measuring the relative satura- ingress from the atmosphere, water concentration in the at- tion of oil one can easily deter- and the aging decomposition of mosphere and in the oil in the mine its absolute moisture con- cellulose and oil. tank, and the viscous flow of wet tent expressed in parts per mil- Residual moisture in a new air into the transformer caused lion (ppm). In this case the water transformer after factory dry out, by the difference between the at- solubility characteristic for the prior to transportation, is expect- mospheric pressure and the pres- specific oil must be known in ed to be less than 1%, with a tar- sure in the tank1. advance. Being a real-time effi-

18 160/2002 cient on-line method, the mois- Water content of paper ture-in-oil measurement has at- insulation tracted a lot of attention in re- cent years. A number of com- One of the aims of the moisture mercially available sensors have assessment of oil-filled power been tested in different condi- transformers was to evaluate the tions using the Monash test rig. water content of its paper insula- Another method for ppm tion. The term “paper insula- determination is a technique tion” is a generic term that de- based on the well-known Karl scribes solid cellulose material, Fischer titration reaction. How- such as paper, pressboard, wood ever, this method is not a real- and cotton. Another term, “wa- time one and requires appropri- ter content of paper (WCP)”, is ate chemical instrumentation for used to quantify the amount of its implementation. It is also water present in paper insula- prone to a high level of error and tion. Traditionally, the term its results are often difficult to WCP refers to a ratio between interpret. A timely and accurate the mass of water and mass of measurement of the oil tempera- dry non-oily paper, expressed in ture should be made when ob- a percentage. The mass of water Figure 1. Moisture Equilibrium Curves relating water-in-paper activity to taining the oil sample. is calculated from the difference active water content of paper for temperatures from 0 to 100 °C. There is also a group of between the masses of wet and methods based on the measure- dry paper. The paper is usually ment and analysis of dielectric dried out in an oven prior to the properties of insulation. Diagno- measurement of the dry paper sis with these methods is based mass. The traditional term WCP on the fact that paper and oil gives a clear meaning for non- change their dielectric properties oil-impregnated paper. when moisture levels increase. For oil-impregnated paper Therefore, by measuring para- the WCP can still be measured, meters such as the dissipation in this case using the Karl Fisch- factor, polarization and depolar- er titration method. Following ization currents (PDC) and re- the measurement of water mass turn voltages (RVM) in the fre- in the Karl Fischer apparatus, the quency and time domains, it is oily paper is degreased and only possible to relate these changes then placed in an oven for dry- to water concentration in a pa- ing. To obtain an accurate meas- per-oil insulation system. How- urement, the thickness of the ever, with most of these meth- piece of paper or strip of press- Figure 2. Moisture Equilibrium Chart as published in “Moisture Equilibrium Charts for Transformer Insulating Drying Practice”.2 ods it is difficult – if not impos- board should not exceed a few sible – to distinguish the effects hundred microns. However, for of moisture on the insulation a paper-oil insulation system from the effects of aging caused with both thin and thick paper ment in operating transformers tent of paper (WCPA)”, was also by other processes. This creates a insulation the situation for was developed, based on a water- introduced. The term WCPA re- lot of confusion over the relia- measuring the WCP is com- in-paper activity concept. The flects the water available in the bility of dielectric response pletely different. parameter of water-in-paper ac- transformer insulation for ex- methods. Interpretation of the In a study conducted at tivity is used to access moisture change between paper and oil. A results still remains more art Monash University under an conditions in both new and old new moisture equilibrium chart than science. EPRI, USA sponsored project, a transformer insulation systems. (shown in Figure 1) relating the new method of moisture assess- Another term, “active water con- parameter of water-in-paper ➤

160/2002 19 - Evaluation of the water-in- A new classification proce-

paper activity (Awp) for the trans- dure was developed to rank, former oil from a population of power - Evaluation of the active wa- transformers, critical transform-

ter content of paper (WCPA) as a ers in terms of moisture for fur-

function of Awp and temperature. ther continuous monitoring. A software application, the The new classification procedure Transformer Moisture Monitor aims to improve the effective- (TMM), has been developed on ness of the management of trans- the basis of the WIP algorithm. former life. The TMM uses neuro-fuzzy The new classification proce- computing to evaluate the con- dure is based on a method of sistency of the moisture sensor moisture assessment that evalu-

output, to access the WCPA, and ates the WCPA and was briefly to alert the user when insulation described in the section above. It conditions require attention. is available in the form of a The TMM acquires data from chart, shown in Figure 3. Values Figure 3. Chart for off-line moisture diagnostics of transformers containing the Vaisala HMP228 Humidity of WCO in ppm represent the new oil. and Temperature Transmitter. results of Karl Fischer (KF) meas- The probe of the transmitter has urements and values of the tem- both moisture and temperature perature T represent the temper- activity to the WCPA was devel- ever, we must measure one more sensing elements at its tip. ature of the oil at the moment of oped. parameter in this case, prior to oil sampling. In Figure 3, values New classification Numerically, water-in-paper the evaluation of the WCPA. of WCPA are distinguished by procedure for off-line activity (Awp) is equal to the equi- This parameter is called the “wa- color. Green corresponds to a moisture diagnostics librium percentage of relative ter solubility of oil S(T)”, or, as WCPA of less than 1%, yellow saturation (RSeq) divided by 100. in Figure 2, the “Solubility Lim- The research conducted at corresponds to a WCPA of be- There are a number of ways it, ppm”. Monash University has shown tween 1% and 2% and red corre- to evaluate the WCPA of paper The moisture equilibrium that, for the accurate moisture sponds to a WCPA of more than insulation in a paper-oil insula- chart in Figure 2 was developed assessment of transformer insu- 2%. The numbers in the squares tion system. One of them is ap- for new oil. The figures around lation, the continuous monitor- represent the diffusion time con- parent from Figure 1. To use the the chart show the water solubil- ing of a number of parameters, stant for moisture across a 1-mm curves of Figure 1 we need to es- ity parameter S(T) for new oil at including transformer load, tem- pressboard plate exposed to oil tablish equilibrium conditions temperatures from 0 to 100 °C perature and oil relative satura- from both sides. The 1-mm in the system and measure the in 10 °C intervals. tion, is required. The measure- pressboard was chosen to reflect parameter of Awp using a relative ment of water solubility charac- the approach of the water-in-pa- saturation (RS) sensor. Assessment of moisture teristic of oil in the transformer per activity applied to the trans- Another way to evaluate the in an operating is also required. former ranking and classifica- transformer WCPA of paper insulation in a A utility may operate tens or tion. paper-oil insulation system is to It is known that an operating even hundreds of transformers. At an oil temperature below use a moisture equilibrium chart, power transformer is never in However, not all of the trans- 45 °C and WCO of less than 20 similar to the well-known mois- moisture equilibrium. Thus, the formers require continuous ppm, the moisture diffusion ture equilibrium chart published two moisture equilibrium charts monitoring. How is it possible to time is too long for the reliable in 2 and shown in Figure 2. in Figures 1 and 2 cannot be ap- identify a transformer with mois- diagnosis according to the pro- The chart in Figure 2 gives plied directly when assessing ture concerns for further moni- posed procedure. To reflect this the relationship between the wa- moisture in the field. To address toring? There is a demand for a fact the bottom left corner of the ter content of oil (WCO) ex- this, a method for the moisture classification procedure, which graph in Figure 3 is shadowed. pressed in ppm, the temperature assessment of transformer insu- would rank transformers by The classification procedure and the “% Moisture in Paper”, lation has been developed. The moisture levels. chart in Figure 3 is valid for oil which, in fact, for thin paper in- method is based on the Monash A traffic light approach is the with a water solubility character- sulation is equal to the WCPA. water-in-paper (WIP) algorithm, EPRI adopted way of ranking istic close to that of new oil. In

Again, to evaluate the WCPA, we which incorporates the follow- the health of plant equipment. the previous section of this pa- need to establish equilibrium ing three steps: Red, yellow and green colors per it was demonstrated that the conditions in the system and - Evaluation of true oil rela- would indicate the ‘wet’, ‘re- water solubility characteristic of then measure the WCO using tive saturation in the trans- quires attention’ and ‘dry’ states new and aged oil can differ sig- the Karl Fischer apparatus. How- former of moisture in transformers. nificantly. This means that for

20 160/2002 the accurate ranking of aged transformers, evaluation of the oil’s water solubility characteris- The determination of tic would be required. moisture in oil is an In light of the new know- essential part of a ledge presented here, the tradi- comprehensive transformer tional approach, which states: “If maintenance the WCO exceeds 20 ppm, the program. transformer requires further at- tention, if the WCO is less than 20 ppm no action is required,” must be reconsidered. From Fig- ure 3 it follows that at WCO=20-25 ppm a transformer with new oil would be consid- ered “probably wet” if the oil sample was taken at a tempera- ture of below 55 °C. However, if the oil sample was taken at a temperature of above 80 °C, with the same WCO=20-25 ppm, the transformer would be considered “probably dry”. To prove or reject the conclusion, one more sample of oil should be taken in the number of hours HMP228 Moisture and Temperature Transmitter for Transformer Oil shown in the related square on the chart. This example illus- he HMP228 Transmitter provides on-line former oil. The water solubility in oil is tempera- trates the importance of the T measurement of moisture and temperature ture dependent: water solubility increases as measurement of oil temperature in transformer oil. The measurement gives con- temperature raises. In addition to traditional during the oil sampling, the im- tinuous information and enables better mainten- ppm-output, the transmitter measures water ac- portance of the second oil sam- ance against transformer failures. tivity. The water activity (aw) indicates directly pling, and the importance of the Vaisala’s microprocessor-based HMP228 whether the oil is too moist. The aw measurement length of time between the two Transmitter is accurate, reliable and fast. The ba- is independent of the type, aging or temperature sampling events. sic model of the HMP228 Transmitter calculates of the oil. G It is apparent that knowledge the average water solubility in mineral trans- of the WCO only, gained from a single Karl Fischer measure- ment, is insufficient for the ac- curate assessment of transformer moisture condition. Knowledge The parameter of the water monitoring is suggested for the References: 1. V. Sokolov and B. Vanin, “Experience of the temperature of the first oil solubility of oil is required for ranking of power transformers with In-Field Assessment of the Water sample, the dynamics of mois- the validation of the moisture by the level of moisture. Red, Contamination of Large Power ture and temperature gained sensor installed in the trans- yellow and green colors would Transformers”, Proceedings of EPRI from the second oil sample, and former. Water-in-paper activity indicate the ‘wet’, ‘requires atten- Substation Equipment Diagnostics the water solubility of the oil are was found to be a factor in deter- tion’ and ‘dry’ states of moisture Conference VII, New Orleans, 1999 also required. mining the state of dryness in a in transformers. The classifica- 2. T. V. Oommen, “Moisture Equilibrium Charts for Transformer Insulating power transformer. tion procedure presented is only Conclusions Drying Practice”, IEEE Trans. on A stand-alone software ap- valid for oil with a water solubil- Power Apparatus and Systems, Vol. Oil type, age and flow rate con- plication called “Transformer ity characteristic close to that of PAS-103, 10, 1984, pp.3063-3067 tribute to the measurement and Moisture Monitor” (TMM) is new oil. For the accurate ranking subsequent accuracy of moisture proposed for the moisture as- of an old transformer, the water assessment in a paper-oil insula- sessment of a transformer. solubility characteristic of the tion system. Sensor positioning A new classification proce- transformer’s oil would need to also contributes to the accuracy dure that aims to identify criti- be evaluated. G of moisture assessment. cal units for further continuous

160/2002 21 Jan Grönblad, M.Sc. (Eng.) Product Line Manager Sensor Systems Division Vaisala Helsinki Finland

Vaisala’s new DM500 Precision SAW Hygrometer has been specifically developed for applications where high accuracy is needed. The DM500 offers reliable measurements and ease of use, enhanced through additional product features, such as the graphical user interface. With excellent measurement performance and an easy-to- use product concept, the DM500 represents a new generation of high accuracy dewpoint measurement instruments.

New technology for high accuracy measurements Vaisala’s DM500 - Dewpoint Reference

he Vaisala DM500 Preci- dard. Due to the rugged sensing ment with excellent repeatability sion SAW Hygrometer technology, the DM500 is also and fast response time. In addi- T offers excellent measure- suitable for use in industrial ap- tion, DEWCAP® technology ment performance with Surface plications, such as metal treat- can withstand particulate con- Acoustic Wave (SAW) technolo- ment processes. The innovative tamination and distinguish dew gy. The DM500 is the best DEWCAP® SAW Sensor offers and frost directly. choice for calibration laborato- the advantage of high accuracy ries and for use as a transfer stan- and reliable dewpoint measure- Product concept The DM500 Precision SAW Hy- grometer consists of a DMI500 User Interface Unit and a DMP501 Dewpoint Sensing Unit. The User Interface Unit in- cludes display, keypad, power source and analog outputs. The Dewpoint Sensing Unit includes the SAW -based sensor and measurement and cooling elec-

With the DEWCAP® sensor condensation on the cooled surface is detected by a high frequency SAW signal which attenuates in dew or frost.

22 160/2002 The DM500 provides highly accurate dewpoint measurement with excellent repeatability. Standard without a Mirror

tronics. Three different installa- Dew/frost causes a distinctly different sig- ergy of this micromechanical tions are available for the determination nal change, thus enabling the de- wave. The SAW detects very DM500: installation in a 19" rack, termination of dew or frost on small amounts of condensate - as remote installation, and use of The DM500 detects the differ- the DM500’s sensor. little as one-tenth of that re- the DM500 as a desktop/portable ence between dewpoint and quired by an optical detection instrument equipped with op- frostpoint at dewpoint tempera- Fast response time system. This means substantially tional handle. tures below 0 °C directly, with- The SAW signal is attenuated by faster response times, particular- out any additional cooling cy- dew/frost, which absorbs the en- ly at low frostpoints. ➤ High measurement cles. In traditional condensation performance hygrometers such as chilled mir- The DM500 is an automatic, rors the optical beam can not see continuously controlling con- the difference in the condensate. densation hygrometer measur- The problem exists when high ing dewpoint temperatures from accuracy measurement has an -75 °C to +60 °C Td with ±0.2 additional uncertainty factor in °C traceable accuracy. For low the typical range –30…0 °C Td. frostpoint measurement, the The presence of liquid condens- DM500 has a connection for ation on the DEWCAP® sensor water cooling. In order to pre- alters the signal in a repeatable vent condensation when meas- way. Freezing the condensate uring high dewpoints it is also equipped with an optional heat- ed gas sampling system and a The DM500 has a high-quality control for external pipeline LCD display with menu -based user heating. interface.

160/2002 23 Withstands Various output James Tennerman contamination variables Business Development Manager Vaisala The DM500 operates reliably The DM500 displays user selec- Boston even with substantial particulate table hygrometric units, such as USA contamination on the sensing dewpoint/frostpoint tempera- element. The SAW signal is sensi- ture, relative humidity, partial tive for condensate (dew/frost) pressure of water vapor, and hu- but not for particulates. mid air volume/dry air volume (ppmv). In addition, the DM500 Salt sensing can measure temperature, pres- Hygroscopic dirt is a common sure and gas flow rate if the in- source of error in conventional strument includes the corre- dewpoint measurement tech- sponding optional sensor. niques as it can change water va- por pressure close to the sensor. Wide variety of The DM500 can detect the pres- additional features ence of salts or hygroscopic dirt The DM500’s display can be How to fully benefit from using the on the sensor surface with its in- switched between numeric or telligent self diagnostics. graphical. The multi-lingual user interface is menu based and very Vaisala DM500 Precisi Chemically durable easy to use. The DM500 also has Use of a quartz wafer as a sensor data-logging capability and is substrate gives excellent resistance equipped with the sophisticated to aggressive chemicals. Wetted MI70 Link Windows® software parts are limited to stainless steel, program for easy PC connec- Good planning is essential for achieving high G silicone, tantalum, vectra polymer tion. performance measurement results with any and quartz. All water absorbing materials are located downstream. metrology tool. Successful application of the Vaisala DM500 Precision SAW Hygrometer is best achieved with a three step planning ap- ® proach. These steps can be described as eval- DEWCAP Sensor and uation, preparation, and execution. Surface Acoustic Wave (SAW)

aisala's DEWCAP® Sensor uses Surface Acoustic Wave (SAW) Evaluation What is the pressure of the V technology to usher in a new generation of condensation hy- Evaluation starts with an under- sample gas? grometers. In Surface Acoustic Wave (SAW) technology the tem- standing of the intended use of • Identifies the need for a perature controlled quartz sensor surface is cooled until dew or the Vaisala DM500 Precision pump option if pressure is frost collects on the sensor surface. The presence or absence of SAW Hygrometer. The results of ambient, condensation is sensed using the SAW instead of the traditional evaluation include a “go” or a • Assures that maximum optical beam used in chilled mirrors. In measuring mode, the tem- “no-go” decision as to the suit- process pressure is within perature of the DEWCAP® quartz surface is varied until condens- ability of the instrument for the safe limits, ation exists in equilibrium. When the equilibrium is reached, the application. In the case of a What is the temperature of the temperature of the sensor surface is measured by a precision Pt- “go,” the correct product confi- sample gas? 100 PRT. This measured temperature equals the dew/frostpoint guration will be evident. The fol- • High temperature gas should temperature of the measured gas. G lowing are critical things to con- be cooled to ambient before sider during the evaluation: measurement, What is the anticipated dew- What is the composition of the ® The DEWCAP sensor is based on innovative SAW technology. point or range of dewpoints to sample gas? be measured? • Assures material • Identifies the correct sensor compatibility with the model and any possible sensor, need for external cooling, What are the desired humidity • Identifies whether elevated parameters for display or out- dewpoints may cause put? condensation in the gas • For %RH, a temperature system, requiring the use of sensor option is required, a heated sensor, • For ppmv or other pressure

24 160/2002 on SAW Hygrometer

sensitive parameters, a used for best results with dew- for gas and coolant connections. The DM500 Precision SAW pressure sensor should be point temperatures below Appropriate line voltage should Hygrometer is an automatic, specified. –30°C. US users will typically be available. continuously controlling want to use 1/4” tubing, com- condensation hygrometer which is Preparation pression fittings, and accessories %RH measurements suitable for calibration laboratories When the suitability of the that are equipped to be connect- Location of the temperature sen- and for use as a transfer standard. DM500 has been established, ed in this way. Other users will sor is important. In general, the preparation takes into account typically specify 6 mm tubing temperature sensor should be in the entire measurement scenario. and fittings. Rubber and/or Ty- the location where the user gon tubing should not be used wants to know the relative hu- Filtration for sampling! midity. the slew rate of the Peltier cool- If substantial particulate con- ers and the rate of water vapor tamination is present in the gas Flow control Execution capture at the process dewpoint. sample, a non-hygroscopic filter Samples at positive pressure will With the DM500 correctly spec- • Maintenance of the sensor should be installed in the sam- require some type of flow con- ified and installed, all that re- should be performed as re- ple line before the sensor. This trol downstream from the sensor mains is to operate and maintain quired. When liquid cooling is minimizes the need for sensor for correct measurement of pres- the system. in use, sensor cleaning should cleaning and keeps the gas chan- sure dewpoint. only be done when the coolant nel free of contaminants that • Cooling water should be circu- temperature is above the ambi- may adversely effect measure- Physical location lating if installed; care should ent dewpoint. ment response time. The DM500 should be located be taken to assure that condens- • Maintenance of the cooling in an environment consistent ation forming inside the sensor system and filtration compo- Fittings & tubing with the specifications. Access to housing is drained. nents should be performed as Stainless steel tubing should be the back of the sensor is required • Response time is a function of required. G

160/2002 25 Meteorological dewpoint measurements from arctic conditions to hot deserts National Weather Service Relies on Vaisala Instruments for Dewpoint Measurement

The National Weather Service (NWS) in the USA has started to update the dewpoint measurement in the ASOS (Automated Surface Observing System) network with Vaisala’s HUMICAP® technology. The high measurement performance over a wide measurement range together with the long maintenance interval were among the most important factors considered when selecting the new- Jan Grönblad, M.Sc. (Eng.) Product Line Manager generation technology for the network. Vaisala’s unique warmed Sensor Systems Division sensor technology was finally chosen to satisfy the most demanding Vaisala Helsinki Finland needs in humidity and dewpoint measurement.

26 160/2002 Vaisala’s 30 years experience with capacitive humidity sensors has resulted in a sensor which satisfies one of the most demanding needs in humidity and dewpoint measurement.

The dewpoint measurement principle in the warmed sensor head. The temperature of the warmed HUMICAP® sensor is measured accurately in addition to the RH measurement. These values result in ambient dewpoint as dewpoint does not change although the temperature of the sensor rises.

beam for radiation shield

radiation shield probe

The dewpoint probe in the specially designed radiation The dewpoint measurement in the ASOS network at shield with open structure. NWS incorporates an installation kit for the sensor head together with an enclosure for the dewpoint transmitter and optical modem. The warmed probe of the transmitter is installed in a radiation shield with open structure.

fter a long evaluation chilled mirror technology with confidence). The measurement warmed sensor technology, the period the National optical dew detection which is technology is also not very sensi- temperature of the HUMICAP® A Weather Service in the known to be sensitive to dirt. tive to dirt and operates with the sensor is measured accurately in United States has started to re- required accuracy over the speci- addition to the relative humidity place its dewpoint measurement Reliable measurements fied wide temperature and hu- measurement from which the instruments with Vaisala’s HU- with low maintenance midity range. dewpoint is calculated. The cal- MICAP® technology through- needs culation results in actual ambient out the ASOS (Automated Sur- The new instrument for dew- Warming prevents the dewpoint, as dewpoint does not face Observing System) network point measurement in the ASOS adverse effects of change although the temperature in the USA. This network covers network is based on warmed moisture of the sensor rises. the entire continent from Alaska HUMICAP® thin film polymer The advantage of warming is a re- Additionally, the long-term to Texas, setting very high de- sensor technology, used in, for liable measurement even in situa- stability provided by HUMI- mands for the instrumentation example, Vaisala HMP240 Series tions where the humidity levels CAP® technology makes the fi- in terms of environmental con- products. The measurement with are close to 100%RH, i.e. the nal product concept unprece- ditions, which range from arctic capacitive thin film polymer sen- moisture in the air starts to con- dented. It allows high-perfor- to hot desert. The sensors that sor is itself very reliable and has a densate and dewpoint equals the mance meteorological dewpoint are being replaced represent very low failure rate. For exam- ambient temperature. Warming measurements with minimal technology with a high need for ple, the MTBF value (mean time ensures the sensor will not get maintenance needs, meeting the maintenance, mainly due to the between failures) for the wet which could result in incor- exacting requirements of the basic operation principle of the HMP243 Dewpoint Transmitter rect humidity readings (too high) NWS surface weather observing instruments. They utilized is more than 18 years (with 2 until the sensor dries up. In system. G

160/2002 27 Heikki Joensuu, B.Sc. (Eng.) Product Development Manager Sensor Systems Division Vaisala Helsinki Finland

When direct dewpoint spot measurement is not possible DSS70A Portable Sampling System

The Vaisala product family of portable dew- point measurement instruments has now been enhanced with a sampling system option. The new DSS70A Portable Sampling System allows measurements to be made in applications where a direct measurement cannot be used. It also allows measurements to be made in the most demanding process- es, with dusty and hot process gas samples.

Compact design DM70 Hand-Held Dewpoint The Vaisala DSS70A Portable Meter family, but can also be or- Sampling System is a battery- dered separately. This complete powered system for portable compact sampling system has dewpoint sampling applications. been built around Vaisala’s The DSS70A system enables DM70 Hand-Held Dewpoint dewpoint measurements to be Meter. made from places where direct The DSS70A is designed to measurement is not possible. provide the greatest amount of The product is an option for the sampling flexibility. A battery- powered pump is used to extract a gas sample. The sample gas then passes through a filter to re- move particulate contamination before measurement. Flow through the system is controlled and monitored with a needle valve and flow meter. The DSS70A is then simply connect- ed to an appropriate sample The DSS70A point where tubing and measure- Portable Sampling System, delivered in a ment results can be monitored carrying case, includes and analyzed with a Vaisala MI70 everything needed for sampling. Measurement Indicator.

28 160/2002 Demanding to adjust sampling rate applications • Changeable filter The DSS70A is designed to work • Clear battery indicator even in very demanding process- • Rechargeable battery or AC es, for example in metal treat- usage ment processes, where the meas- • Graphical trend display ured air sample is very hot and • Sophisticated data collection dirty. In plastic dryer applica- functions including Windows® tions a DM70 Hand-Held Dew- software point Meter together with a DSS70A Sampling System is an Measurement reports optimum tool to check the dryer made easy is working properly. The Vaisala MI70 Measurement Indicator offers many handy fea- Performance tures to analyze and collect data • Wide measurement range – during measurement. The indica- from -60 °C to +60 °C tor has numeric and graphic dis- • Fast response time between play modes to follow the process start-up from ambient condi- trends. Measurement results can tions to low and high process be stored in the memory and dewpoints then later easily transferred to a • Standard process connections PC at the office, using the op- 1/4" SWAGELOK® tional Windows® software. G Mechanics Engineer Kari Bergman of Vaisala checks an injection moulding • Flow meter and needle valve plastic dryer at Plastoco Oy.

160/2002 29 essy Plastics Corporation houses a white room and a clean The Advanced Manufacturing is a custom plastics injec- room, with post molding, engi- Facility Maintenance Supervi- T tion molder headquar- neering, design and tool build- sor, Todd Eaton, who is respon- tered in Elbrige, New York ing capabilities. sible for the maintenance of the (USA). The company manufac- In order to be able to moni- plant production machinery, tures products for the medical, tor the operation of plastic air plant facilities, plant engineering automotive and electronic in- dryers, Tessy Plastics use two and process improvement, dustries, amongst others. Beside Vaisala DM70 Hand-Held Dew- stresses that the plastic dryers the plant in New York, Tessy point Meters. The DM70 meas- must operate with dewpoints be- Plastics Corporation has facili- ures dewpoint accurately in a low -40°F (-40°C) continuously ties in Virginia and China. The wide measurement range, which for proper plastic drying. “Since facility in Central New York is important in this application. the first DM70 unit was pur- chased in January 2002, addi- tional instruments have been in- stalled in our plant and in the Precision plastic injection moulding requires drying systems,” remarks Mr. Eaton. The plant is also equipped Accurate Monitoring of with a DMT242 Dewpoint Trans- mitter that was purchased to up- grade one of the dryers. To moni- Plastic Drying Process tor a dehumidification unit, a Vaisala DMP248 Dewpoint In plastic production plants, dewpoint measurement is essential for Transmitter is used. Moreover, a HMP233 with a radiation shield monitoring the drying process. Tessy Plastics Corporation’s state-of- is used to monitor outside condi- the-art facilities have been equipped with Vaisala dewpoint measure- tions, measuring the wet bulb ment instruments for their drying units, with Vaisala technology also and enthalpy of outside air. This relied upon to cater for other measurement needs in their facility. instrument allows the maximiza- tion of free cooling potential us- ing outside air. Additionally, the HVAC system at the plant is fit- ted with HMW40s that were re- cently installed. Todd Eaton finds that Vaisala products offer excellent accuracy and repeatability. Moreover, the ability to be interfaced with PCs is important. “The instruments allow the recording and tracking of dewpoints and other measure- ments, which in turn allows us to operate our equipment more ef- fectively and efficiently,” Mr. Eaton explains. Vaisala instru- ments have performed very well and proven excellent for the company. G

At Tessy Plastics, Todd Eaton uses Vaisala DM70 Hand-Held Dewpoint Meters to monitor the plastic dryers.

30 160/2002 Jan Grönblad, M.Sc. (Eng.) Product Line Manager The regulations for equipment used in hazardous areas Sensor Systems Division where there is a risk of explosion vary slightly in different Vaisala Helsinki parts of the world. The Vaisala HMT360 Series Humidity Finland and Temperature Transmitter used in hazardous areas has now received local approvals in three new countries. New approvals have been awarded to HMT360 by Factory Mu- tual in the USA, TIIS in Japan and Test Safe in Australia.

Safe measurements in hazardous areas HMT360 Series Receives New Approvals

range of local approvals for and contribute to the benefits of HMT360 Series Transmitters. In various industrial sectors in addition to the European ap- Japan. proval ATEX100a from PTB TestSafe approval in Au- (Physikalisch-Technische Bundes- stralia is the most recent ap- anstalt/Federal Institute of proval for HMT360 Series Physics and Metrology in Ger- Transmitters. TestSafe Australia many), the HMT360 series now is a safety testing and research fa- has approvals from Factory Mu- cility which offers manufacturers tual in the USA, TIIS in Japan and suppliers a comprehensive and Test Safe in Australia. range of safety testing, certifica- In industrial applications in tion, and approval services in the USA, Factory Mutual (FM) the electrical, electronic, me- is an authority on approving in- chanical and personal protective struments for use in potentially equipment fields. Certificates explosive atmospheres. Factory and approvals at TestSafe are is- Mutual Research electrical sued for conformance with Aus- equipment testing is based on tralian Standards and legislative Factory Mutual Research stan- requirements. dards, American National Stan- For hazardous areas the dards Institute (ANSI) Stan- Vaisala HMT360 Series Humidi- dards, and International Elec- ty Transmitters are indispensa- trotechnical Commission (IEC) ble. They represent the latest The HMT360 provides he Vaisala HMT360 Se- Standards. measurement technology and accurate measurements and ries Industrial Humidity In Japan, the Technology In- fulfil safety requirements laid safe operation on hazardous T and Temperature Trans- stitution of Industrial Safety (TI- down in a wide variety of coun- installation sites. mitter was launched in 1999 IS) has also approved the tries. The thorough studies made with the European EEx approval HMT360 Series. TIIS is a non- on the HMT360 Transmitter for use in hazardous areas. governmental, non-profit, self- guarantee the safety of high-per- However, global needs in this sustaining organization which is formance humidity and temper- strictly controlled application recognized by the Ministry of ature measurements, even in in- area do not necessarily follow Labor as a juridical incorpor- stallations with continuous ex- European regulations. This has ation. The objective of TIIS is to posure to the most easily ignited caused the need to expand the help reduce industrial accidents flammable gases. G

160/2002 31 Ritva Siikamäki, MA Editor-in-Chief, Vaisala Helsinki finland

Major program to enhance national weather observation network China Meteorological Administration Invests in Accurate Vaisala Barometers

China Meteorological Administration, CMA, is implementing a project around China called “Atmosphere Automatic Monitoring System”. The objective is to set up a nationwide monitoring network of weather observation stations, in three different categories, to form a network.

ccording to its 10th munication of CMA, which is five-year plan (2000— the topmost management office A 2004), China Meteor- for meteorology in China, or- ological Administration (CMA) ganized a comparison test for ba- has started to implement a proj- rometer performance. The At- ect called Atmosphere Automat- mosphere Sounding Research ic Monitoring System, which ex- Centre of China Meteorological tends over the entire country. Science Institute was responsible The project aims to set up three for the test design, setup, imple- classes of weather observation mentation and data collection. station and a monitoring net- The comparison started with la- work. The top-level stations, boratory tests in 2000, with field which are called national stan- tests then carried out from No- dard stations, will be the main vember 2000 to November 2001. weather observation bases in the They focused on the barometers’ monitoring network. Totaling temperature stability and overall more than one hundred, these long-term stability. stations will be equipped with The objective of the extensive the hardware needed to improve The China National Meteorological Center which was responsible for the test test period was to choose which accuracy and long-term stability. is located in Beijing. one or two pressure sensors The second grade of station are would be most suitable for inte- called basic stations and will be gration into the domestically set up around China to raise the sity and acquire more data. The pressure measurement in the up- manufactured automatic weather weather observation ability and automatic weather stations to be per level stations. stations. Additionally, the aim the density of observations. The employed at these three classes was to improve the quality of air third category of station, so- of station will be manufactured Extensive comparison monitor prediction in China and called general stations, will total in China. However, sub-assem- of barometers to lighten the staff’s workload, as more than 1000. The general sta- blies and measurement instru- To improve the implementation well as to raise atmospheric fore- tions will perform observations ments of foreign manufacture of this project, the Department casting accuracy and the level of to further increase network den- will be utilized, for instance for of Observations and Telecom- automation in performing obser-

32 160/2002 Barometers were tested on site for their stability,

vations in China. Some leading was much appreciated due to its barometer manufacturers from advanced technology and long- around the world and China ap- term stability, proven in a 10- plied for participation in this trial month test in western rural areas and test. of Beijing. Since then Vaisala has also provided CMA with RS80- Vaisala barometers 15G Radiosondes, RT20 Radio- participated theodolites, DigiCORA Sound- Vaisala sent 3 units of PTB210 ing Systems with GPS wind find- and PTB220 Barometers to be ing, and a number of other assessed in the trial. The Vaisala weather observation products. In PTB210 series of barometers are 1997 Vaisala provided the Qing- intended for direct outdoor in- hai province with key hardware stallations. They operate in a for a project called Disaster wide temperature range, with the Weather Monitoring Network, electronics housing protected to with the help of a loan from the IP65 class against sprayed water. Finnish government. Vaisala’s The PTB220 Series Digital Beijing office often arranges sem- Barometers cater for measure- inars on various topics to intro- ments in a wide environmental duce state-of-art meteorological pressure and temperature range. technologies. Vaisala also invites Both the PTB210 and PTB220 experts and officials of all levels series of barometers are used to visit the production plant in widely in, for instance, weather hundred units have been deliv- important customers in China. Finland. Their high-performance stations, data buoys and ships, ered to CMA. The various cooperation projects products have proven that and are based on the BARO- between CMA and Vaisala trace Vaisala is one of the world’s best CAP® pressure sensor. All six Extensive cooperation back to the founding of Vaisala’s companies in the field of meteor- barometers showed very good between CMA and Beijing Representative Office in ology. Consequently, they have performance during the trial and Vaisala 1994. A set of MILOS 500 pro- won the confidence of Chinese test. During the on site field tests CMA is one of Vaisala’s most vided to CMA in August 1994 meteorological customers. G trial, all barometers were in- stalled in wind, rain, snow and shockproof test chambers under the same static pressure. Comparison proved high performance of Vaisala barometers The high reliability, accuracy and good stability of the Vaisala PTB210 and PTB220 Digital Barometers in this comparison proved once again that Vaisala products offer excellent quality. The good performance of the PTB series barometers was one of the most crucial factors for CMA in their selection and pur- chasing process. After compre- Vaisala's PTB220 Digital Barometers are designed for hensive comparison and assess- measurements in a wide ment CMA decided to purchase environmental pressure and PTB220 barometers. Several temperature range.

160/2002 33 The PTU200MIK1 offers easy installation of equipment at an outdoor site.

PTU200MIK1 Meteorological Installation Kit Easy Measurements on Site

The Vaisala PTU200MIK1 Meteorological Installation Kit is a high- quality mounting kit for outdoor use of PTU200 Barometric Pressure, The Vaisala SPH10 and SPH20 Relative Humidity and Temperature Transmitter. It allows meteorol- Static Pressure Heads are designed ogical measurements to be made on site, e.g. next to a GPS antenna. to minimize the errors in barometric pressure measurement caused by The PTU200 Transmitter belongs to recommended equipment of the variations in wind speed and SuomiNet network, an international network of GPS receivers. direction.

he PTU200MIK1 Mete- tects the relative humidity and which records temperature, baro- orological Installation temperature probe of PTU200 metric pressure and relative hu- T Kit allows easy outdoor and the SPH10 Static Pressure midity. mounting and installation of the Head reduces the effect of wind One of the approved MET PTU200 Barometric Pressure, on the pressure measurement. instruments for the meteorolog- Relative Humidity and Tempera- ical observations is the Vaisala ture Transmitter. The kit consists Approved for SuomiNet PTU200 Barometric Pressure, of a protective transmitter box, SuomiNet is an international Relative Humidity and Tempera- support arm, a radiation shield, network of GPS receivers, locat- ture Transmitter. The PTU200 the SPH10 Static Pressure Head, ed primarily at universities. It Transmitter uses the very stable, pole attachment clamps, and a generates near real-time esti- silicon-based BAROCAP® pres- pressure hose. The kit can be at- mates of precipitable water va- sure sensors and requires calibra- tached to any pole with diameter por in the atmosphere, total tion only infrequently. The of either 2" or 50 mm. The box electron content in the iono- PTU200 central unit can be in- offers IP65 (NEMA 4) protec- sphere, and other meteorolog- stalled indoors with its display tion for the transmitter. It is air- ical and geodetic information. and keypad, or outdoors with tight and connected to the static Each SuomiNet site has a dedi- the optional PTU200MIK1 out- pressure head with the pressure cated meteorological measure- door installation kit. G hose. The radiation shield pro- ment package (MET package)

34 160/2002 Tuomas Laurila Senior Researcher Finnish Meteorological Institute Helsinki Finland

Surge in studies on Carbon Cycles of the Ecosystems of the World

Interest in the global carbon cycle has grown greatly in recent years. Mankind is completely dependent upon primary production and in- teracts with the biota through different activities, such as agriculture, forestry and fish farming. The production of these basic resources will be very much affected by climate change and the growing human population.

n the 1990s, emissions of carbon dioxide from fossil I fuel and cement production were, on average, 6.3 PgC (one PgC = one petagram of carbon = 1 billion tonnes of carbon) per year (IPCC, 2001)1. The rate of

increase in atmospheric CO2 concentration has been, on aver- age, 1.5 ppm per year, which cor- responds to 3.2 PgC per year in atmospheric storage. It is esti- mated that oceanic uptake is 1.7 PgC per year. To reach a balance, there has to be a net sink of at-

mospheric CO2 to terrestrial areas that amounts to about 1.4 PgC per year. Land use changes, especially deforestation in tropi-

cal regions, cause a net CO2 re- lease to the atmosphere that was estimated to be about 1.7 PgC per year during the 1980s. From inversion modeling of atmos-

pheric CO2 concentrations and isotopic studies, we know that

Figure 1. Most of the multiyear micrometeorological CO2/H2O flux sites have provided data to the FLUXNET- there is a large net sink (about 2 network, which has a Data and Information System unit at Oak Ridge National Laboratory, Tennessee. PgC per year) to the terres- ➤

160/2002 35 Figure 2. Flux measurement site on a field at Jokioinen in southern Finland. The soil at this site is peat and one of the objectives of the study is to measure the decomposition rate of the peat and compare it to the carbon uptake by the cultivated plants. The sonic and inlet tube to the CO2/H2O monitor is mounted on a boom on top of the short mast. The monitoring and data acquisition computers are housed in a box on the ground. The other mast is equipped with meteorological sensors such as radiation components, temperature and humidity sensors. Also, soil temperature, moisture and heat flux to the soil are measured. During the growing season, CO2 efflux from the soil uptake by plants is also measured by chambers to get data for ecosystem models.

trial biota, which is mostly locat- induced emissions. The Kyoto tools for carbon sequestration vide information on CO2 bal- ed in temperate and boreal re- Protocol remained on a rather monitoring, because of different ances at regional level. The cal- gions of the Northern Hemi- general level. The negotiations measurement approaches and culations are based on inversion sphere. The reasons for this up- thereafter, on how to define the limited understanding of the modeling, which has many limi- take are nitrogen deposition and which biological sinks may be processes. tations and relies on additional increasing atmospheric CO2 con- considered in the calculations, data. centration, which act as fertiliz- were long and difficult at many Carbon dioxide budget Measurements of changes in ers. Recent studies indicate that international conferences before measurements stock of biomass are a direct way land use changes, especially the the final text was approved in There are several ways to study to monitor carbon uptake. It is a forestation of abandoned agri- the Marrakech Accord in 2001. carbon balances at different straightforward, though labor-in- cultural land, are also important Many nations would like to scales, but all of them have se- tensive, task to measure the contributors. facilitate reduction of their emis- vere limitations. The global CO2 changes in tree trunk biomass sion burden through using car- budget mentioned above is every 5 years or so. Because most International bon sequestration by vegetation. based on the very accurate at- of the carbon is stored in the cooperation to The problem is our insufficient mospheric CO2 concentration soil, it is a practically impossible reduce emissions knowledge of where the sinks are measurements, which are per- task to measure changes in this To combat global warming, sub- located and how they may formed on global measurement carbon reservoir. stantial reductions of fossil fuel change in the future. Our under- networks. The Global Atmos- emissions are needed. In Kyoto standing is very much lacking in phere Watch (GAW) network, Micrometeorological 1997, nations agreed upon an in- which land-use classes they are coordinated by the World flux measurement ternational protocol that aims at related and how forestry or agri- Meteorological Organization methods worldwide reductions of CO2 cultural practices may increase (WMO), and the network run Micrometeorological flux meas- emissions. To assist in reaching or decrease the sequestration. It by the CMDL group in the Na- urement methods offer an inter- an agreement in negotiations, it is stated that the sinks should be tional Oceanic and Atmospheric esting way to study CO2 fluxes in was decided that additional ter- verifiable, which is a normal Administration (NOAA) in the a scale that is comparable to the restrial sinks might be partly condition in international agree- U.S., are the most important size of a typical ecosystem, for used to compensate for anthro- ments. However, it will be a very sources of this data. However, example 30 hectares. The core of pogenic emissions, i.e. human- challenging task to develop the the network is too scarce to pro- a standard set-up is a fast-re-

36 160/2002 Figure 3. Annual cycle of CO2 fluxes between the agricultural field at Jokioinen and the atmosphere in 2001. The half-hourly flux values in winter and spring show flux upward (positive numbers) when the peat is gradually decomposing. Barley was sown at the end of May and negative fluxes during the day

(CO2 uptake) appear in June reaching their maximum in mid-

July. In August, the crop ripens and the CO2 uptake gradually ceases. Harvest took place in September. Positive fluxes are highest during nights in summer when heterotrophic efflux from soil and autotrophic maintenance respiration from plants have their seasonal maximum. A typical feature of the micrometeorological observations is that the time series are not complete because of technical problems and an absence of turbulence during calm periods. These gaps have to be filled before long-term averages are calculated, which is one source of uncertainty. Outlayers typically result from non-ideal turbulent conditions. After gap filling the data, we can calculate the annual balances in 2001. This agricultural field on organic soil lost 200 g C m-2 to the atmosphere and 160 g C m-2 was transported away in harvest as grains, resulting in a total yearly carbon loss of 360 g C m-2. We can estimate that during the growing season, carbon uptake by plants and respiration from soil were both about 550 g C m-2.

sponse sonic anemometer and a carbon fluxes. Micrometeoro- many applications. These are nual net balances. Remote sens- fast-response (5-10 Hz) logical flux measurement is the usually measured with different ing from space will be a central

CO2/H2O monitor, which are only tool to get daily and annual kinds of chamber systems. tool in the verification of the Ky- located several meters above the balances, which are obtained by oto Protocol. However, remote ecosystem to be studied. Direct summing up half-hourly obser- Fluxnet for global sensing measurements are entire- observation of the flux between vations. These measurements measurements ly indirect and they have to be the atmosphere and an ecosys- have provided a great deal of After the development of field- supported by extensive model- tem, including trees, undervege- quite new information on the in- proven instrumentation and data ing activities and ground-based tation and soil, is obtained at 30- terannual variation of carbon acquisition systems for flux reference measurements if we min. (half-hourly) resolution as fluxes and the factors behind measurements during 1990s, the aim to reach reliable net carbon a covariance between the verti- these variations. The drawback network of permanent sites is ex- balance estimates. G cal wind speed and gas concen- of the method is the fact that to panding. The sites are usually run tration variations in a turbulent establish and run a station is not by research groups at universities References: flow field. cheap. The costs for equipping a as a part of their ecophysiological A great advantage of mi- station lies at around 100 000 studies. Most of the multiyear 1. IPCC, 2001: Climate Change 2001; The Scientific Basis, Cambridge Uni- crometeorological measure- EUR and, usually, service visits sites are part of a global network versity Press, Cambridge, 881 pp. ments is that measured fluxes are needed several times a week. FLUXNET (http://www-eosdis. may be used in process studies In addition to flux measure- ornl.gov/FLUXNET/). There and model verification. For ex- ments, measurements of other are also regional networks such ample, temperature response of physical and biological parame- as CARBOEURO in Europe ecosystem respiration, light use ters have to be conducted for a (http://www.bgc-jena. mpg.de/ efficiency of CO2 assimilation or profound understanding of the public/carboeur/) and AMERI- effects of drought on carbon bal- functioning of the ecosystems. FLUX in America. ances, may be plotted from ob- The instrumentation to obtain The main task of these sta- servations. Water vapor fluxes, information on CO2 fluxes of tions will be to act as reference which are measured in parallel, different components, leaves, sites to support the global en- tie hydrological processes, evap- stems, roots, ground vegetation deavor to reach a better under- oration and transpiration to the and soil, are also needed for standing of CO2 fluxes and an-

160/2002 37 Christer Helenelund Product Line Manager Sensor Systems Division Vaisala Helsinki Finland

GM70 Hand-Held Carbon Dioxide Meter Versatile Carbon Dioxide Meter for Professional Use

The Vaisala GM70 Hand-Held Carbon Dioxide Meter measures carbon dioxide accurately and is available for several measurement ranges between 0...2000 ppm and

0...20% CO2. The GM70 can be used in various spot-check- ing applications, including laboratories, greenhouses and mushroom farms, as well as HVAC applications. The GM70 incorporates Vaisala's advanced CARBOCAP® Sensor, which enables reliable and stable measurement.

he Vaisala GM70 Hand- has a wide selection of measure- held Carbon Dioxide ment ranges, from low concen- Meter is a versatile meter trations up to 20% of CO . Due T 2 for measuring carbon dioxide to its short warm-up time, the gas concentration. The GM70 GM70 is ideal for spot-checking Hand-Held Carbon Dioxide measurements. The meter can al- Meter GM70 can be used in vari- so be used as a tool for checking ous spot-checking applications Vaisala’s fixed GM20 and including laboratories, green- GM220 Series CO2 transmitters. houses and mushroom farms. In addition, the GM220 Series The GM70 can also be used in transmitters can be adjusted us- HVAC applications. In addition, ing the GM70. Optional, ready- the meter can be used as a cali- to-use Windows® software pro- The GM70 is small and bration check instrument for vides an easy way to handle lightweight, yet rugged. It is an ideal choice for even the most demanding Vaisala’s GM20 and GM220 Se- measurement data in a PC envir- of applications. ries fixed carbon dioxide instru- onment. A built-in power saving ments. The GM70 is small and feature extends battery opera- lightweight, yet rugged, and tion time during data-logging, therefore is an ideal choice for making it possible to collect even the most demanding of ap- CO2 data in locations without plications. mains power. The GM70 has a versatile The GM70 Meter uses the easy-to-use menu based user in- same interchangeable probes as terface, a clear graphical backlit Vaisala’s GM220 Series industri- from low concentrations to high LCD display and a data-logger al transmitters. By plugging dif- concentrations. This feature function, all of which make han- ferent probes into the GMH70 makes the GM70 extremely suit- dling measurement data easy. Handle the user can easily able for various CO2 measure- The GM70 is configurable and change the measurement range ment applications. G

38 160/2002 The calibration reminder program offers an easy-to-use calibration service with standard pricing.

the need to calibrate the instru- ment along with instructions on how to proceed. The instru- ments are sent to a Vaisala serv- ice center for calibration. To ver- ify the results, customers receive two calibration certificates: one that is produced before the ad- justment and one after. This al- lows for the monitoring of the instrument’s performance. Cali- brated products will also be marked with a sticker indicating the date of calibration and rec- ommended date for the next cal- ibration. Calibration reminder program helps to A service to meet customers' needs Two levels of calibration service Maintain Lifetime are available to cater for differ- ent customer needs: standard service calibrations and accredit- Measurement Accuracy ed calibrations from an accredit- ed laboratory. Janne Kivilaakso of Vaisala, Sensor Systems Divi- Besides providing high-performance products, Vaisala aims at sup- sion, who is responsible for the porting the lifetime accuracy of the instruments by making regular service product line, says that in essence the calibration reminder calibrations easy and affordable. The calibration reminder and service program is about making cus- program offers both standard and accredited calibrations, enabling tomers’ lives easier. They no customers to get the best possible performance out of their products. longer need to worry about re- membering calibration and in- stead can concentrate on their core operations. Using the easurement instru- on the instrument, the required vance of the approaching time Vaisala calibration service means ments must be cali- accuracy and the environment for calibration. they don't need to invest in the M brated regularly to where measurement takes place. There are many ways to join equipment or staff needed for ensure accuracy, since the physi- the calibration reminder pro- calibration. The calibration re- cal and electrical properties of Effortless but efficient gram. All new instruments minder program offers an easy- materials do not remain con- calibration shipped from Vaisala include a to-use calibration service with stant. Calibration means com- The calibration reminder pro- registration card where the user standard pricing where costs are paring the reading of an instru- gram allows customers who use can fill in product details and already known. Traceability to ment to a valid reference value. Vaisala relative humidity, dew- their contact information and international standards is also If the reading is not in line with point, material moisture, baro- return it to Vaisala. Customers easily available using the service. the reference value the instru- metric pressure, carbon dioxide can also register on the Vaisala We are also offering optimized ment needs to be adjusted. In and ammonia measurement in- website. Confirmation will be service contracts, including cali- adjustment, the reading of the struments to easily have their in- sent to those who register and bration and maintenance, to instrument is changed to corre- struments calibrated. After join- then, when it’s almost time for meet the needs of customers spond to the reference value. ing the program they get notifi- the recommended calibration, who use a large number of The calibration interval depends cation to remind them in ad- they will receive a reminder of Vaisala products. G

160/2002 39 Europe Vaisala Inc. Columbus Operations VAISALA Oyj 7450 Industrial Parkway P.O. Box 26, FIN-00421 Helsinki Plain City, Ohio 43064-9005 FINLAND USA Telephone: +358 9 894 91 Telephone: +1 614 873 6880 Telefax: +358 9 8949 2227 Telefax: +1 614 873 6890

Vaisala Malmö Vaisala Inc. Drottninggatan 1 D Boulder Operations S - 212 11 Malmö 8401 Base Line Road SWEDEN Boulder, CO 80303-4715 Telephone: +46 40 298 991, USA in Sweden: 0200 848 848 Telephone: +1 303 499 1701 Telefax.: +46 40 298 992, Telefax: +1 303 499 1767 in Sweden: 0200 849 849 Vaisala Inc. Vaisala GmbH 5600 Airport Boulevard Schnackenburgallee 41 Boulder, CO 80301-2340 D-22525 Hamburg USA GERMANY Telephone: +1 303 443 2378 Telephone: +49 40 839 03 0 Fax: +1 303 443 1628 Telefax: +49 40 839 03 110 Vaisala Inc. Vaisala GmbH Sunnyvale Operations Bonn Office 1288 Reamwood Ave. Adenauerallee 46 a Sunnyvale, CA 94089-2233 D-53110 Bonn USA GERMANY Telephone: +1 408 734 9640 Telephone: +49 228 912 5110 Telefax: +1 408 734 0655 Telefax: +49 228 912 5111 Vaisala-GAI Inc. Vaisala GmbH 2705 East Medina Road Bremerhaven Office Tucson, Arizona 85706, USA Buchtstrasse 45 Telephone: +1 520 806 7300 27570 Bremerhaven Telefax: +1 520 741 2848 GERMANY U.S. Toll Free 1 800 283 4557 Telephone: +49 471 170 1655 Telefax: +49 471 170 1755 Vaisala Inc. Regional Office Canada P.O. Box 2241, Station "B" Vaisala GmbH London Stuttgart Office Ontario N6A 4E3 Pestalozzi Str. 8 CANADA D-70563 Stuttgart Telephone: +1 519 679-9563 GERMANY Telefax: +1 519 679-9992 Telephone: +49 711 734 057 Telefax: +49 711 735 6340 Asia and Pacific Vaisala Ltd Birmingham Operations Vaisala KK Vaisala House 42 Kagurazaka 6-Chome 349 Bristol Road Shinjuku-Ku Birmingham B5 7SW Tokyo 162-0825 UNITED KINGDOM JAPAN Telephone: +44 121 683 1200 Telephone: +81 3 3266 9611 Telefax: +44 121 683 1299 Telefax: +81 3 3266 9610

Vaisala Ltd Vaisala KK Newmarket Office Osaka Branch Unit 9, Swan Lane Thick Land Building 1203 Exning 2-3-5 Nanba Chuo-ku, Osaka 542-0076, Newmarket JAPAN Suffolk CB8 7FN Telephone: +81 6 62123954 UNITED KINGDOM Telefax: +81 6 62123955 Telephone: +44 1638 576 200 Telefax: +44 1638 576 240 Vaisala Pty Ltd 3 Guest Street Vaisala SA Hawthorn, VIC 3122 2, rue Stéphenson (escalier 2bis) AUSTRALIA F-78181 Saint-Quentin-en-Yvelines Telephone: +61 3 9818 4200 Cedex Telefax: +61 3 9818 4522 FRANCE ABN 58 006 500 616 Telephone: +33 1 3057 2728 Telefax: +33 1 3096 0858 Vaisala Beijing Representative Office Wangfujing Grand Hotel Vaisala SA Room 518 - 520 7, Europarc Ste-Victoire 57, Wangfujing Street F-13590 Meyreuil Beijing 100006 FRANCE PEOPLE'S REPUBLIC OF CHINA Telephone: +33 4 4212 6464 Telephone: +86 10 6522 4041 Telefax: +33 4 4212 6474 +86 10 6522 4050 +86 10 6522 4151 Telefax: +86 10 6522 4051 North America Vaisala Regional Office Malaysia Vaisala Inc. Level 36, Menara Citibank 100 Commerce Way 165 Jalan Ampang Woburn, MA 01801-1068 50450 Kuala Lumpur USA MALAYSIA Telephone: +1 781 933 4500 Telephone: +60 3 2169 7776

Telefax: +1 781 933 8029 Telefax: +60 3 2169 7775 C210020en 2002-09