Vaisala News175 / 2007

Maintaining harvest fresh apples - Controlled Atmosphere storage requires accurate carbon dioxide measurements Producing oxygen for some serious “paperwork” - Vaisala contributes to a trouble- free air separation process Watch your home like a hawk - WeatherHawk home automation solutions incorporate Vaisala’s weather measurement know-how Bringing out the beauty of wood - Veneer drying with humidity control Contents Vaisala in Brief – We develop, manufacture 3 Business not as usual and market products and services for environmental and 4 Maintaining harvest fresh apples industrial measurements.

6 Keep it cool – Th e purpose of these measurements is to provide a 8 A perfect combination of old and new basis for a better quality of life, cost savings, environmental 9 Extend your measurement range protection, improved safety and better performance. 11 A breath of fresh air Controlled Atmosphere (CA) – We focus on market seg- storage is a widely used tech- 12 Producing oxygen for some serious “paperwork” ments where we can be the nique for long-term storage of world leader, the preferred freshly picked fruits and vegeta- supplier. We put a high pri- bles. Page 4. 14 Clean beach, happy swimmers ority on customer satisfac- 15 Watch your home like a hawk tion and product leadership. We secure our competitive 17 Bringing out the beauty of wood advantage through econo- mies of scale and scope. 19 Vaisala engineers a solution

20 Cool down, the environmental way Cover photo: Shutterstock 23 Coping even with chemical interference

24 Detect moisture in oil Editor-in-Chief: Home automation has evolved Marikka Nevamäki over the past 15 years from 28 Small device - big performance remote lighting and audio/visual controls to very sophisticated Publisher: total environment home control 29 Strong under pressure Vaisala Oyj systems. Page 15. P.O. Box 26 30 Brieﬂ y noted FI-00421 Helsinki FINLAND

Phone (int.): + 358 9 894 91

With today’s growing focus on Telefax: global warming and the need + 358 9 8949 2227 to reduce energy consumption, evaporative cooling needs to be revisited as an important cooling Internet: alternative. Page 20. www.vaisala.com

Design and Artwork: Sampo Korkeila

Printed in Finland by: SP-Paino

ISSN 1238-2388

2 | Vaisala News 175 / 2 0 07 With today’s growing focus on the need need the on focus today’sgrowing With Business not as usual goal the with continues work FECC Conference held in Finland in August. The that project two-year a is (FECC) China - partici Vaisala markets. Chinese the in nology available nology to solve their mounting best environmental know-how and - tech not is Itpopular.increasingly becoming markets are strong experiencing growth, speak forment themselves. also is it generations, future for ment h calne Cias environmental China’s challenge. the the energy itself. The returns on invest- on returns The itself. energy the energy- consumption, energy reduce to mental companies and research organi- research and companies mental than less cost measures efficiency term, long- the In businesses. for strategy tive pated in the China - Finland Cleantech Cleantech Finland - China the in pated rmr eape f h mgiue of magnitude the of example primary zations to meet and exchange ideas. The and the Chinese wish to make use of the aims to build a network involving Finnish about improving efficiencyand reducing conference provided a venue for environ - Energy business. good short, in - costs environmental problems. environ- the preserving of matter a only environmental businesses, like Vaisala, like businesses, environmental cost-effec a - be to proved has efficiency are solutions technological efficient The Finnish EnvironmentalCluster for nry sus n hn peet a present China in issues Energy of Vaisala is the global leader in environ- in leader global the is Vaisala in pulp bleaching, contributing to more to contributing bleaching, pulp in beneficial for all parties. parties. for all beneficial business that is - not as usual - but more mental protection, safety, protection, mental and efficiency that technologies measurement mental in Viaa qimn hls o to you helps equipment Vaisala tion. to reward you with increasingly better increasingly with you reward to strive WeVaisala. with business do to choosing for customers, our you, thank follow follow the accustomed, environmentally right partners and support. partners right cooperation concrete some reporting ec te et eut tcnlg can technology results best the reach provide. CO2 of use energy-efficient and pensive environ life, of quality better promote presented in this magazine, are the inex are the magazine, this presentedin as a refrigerant, and the use of oxygen of use the and refrigerant, a as cooling solutions. Other examples, also also examples, Other solutions. cooling to tools provides Vaisala cost-savings. issues. energy-efficiency in role cant country’s havenot does todevelopment eeomn cn o adi-ad A hand-in-hand. go can development environmentally friendly paper produc paper friendly environmentally the with provided if path, destructive support energy-efficient heating and heating energy-efficient support success stories in the near future.success stories near in the support and services. Let’s continue to do Advanced technology plays a signifi- a plays technology Advanced cnmc rwh n sustainable and growth Economic I would like to take this opportunity to to opportunity this take to like would I n - - - CEO Kjell Forsén 175 / 2007 News Vaisala | 3

President’s column Penny Hickey Application Engineer Vaisala Woburn, MA, USA

Maintaining harvest fresh apples Controlled Atmosphere storage requires accurate carbon dioxide measurements

Controlled atmosphere (CA) storage is a widely used technique for long-term storage of freshly picked fruits and vege- tables. Historically, CA storage has been the primary method for the long-term storage of apples. Through a biological process called respiration, apples take in oxygen and generate carbon dioxide, water, and heat. Controlled Atmosphere storage is an entirely natural process that reduces the effects of respiration to a minimum by controlling the environmental conditions surrounding the stored fruit. CA storage makes it possible to buy crisp, juicy apples year round. Many cultivars of apples can be preserved for a remarkable 9 – 12 months in CA storage, as opposed to only 2 – 3 months if using refrigerated storage. Optimal conditions important In order to effectively preserve apples the storage atmosphere must have a controlled amount of humidity, oxygen (O2), carbon dioxide (CO2) and temperature. The essence of CA storage is the range for O2 and CO2 concentrations, which both must be kept between 0.5 to 2.5%. The precise optimum concentrations vary for different varieties of apples (i.e. Golden Delicious apples may need different conditions than Jonagold apples, etc). The relative humidity is kept in the range between 90 to 95%. High relative humidity slows down water loss and enhances storage life of the produce, but humidity too close to saturation encour- ages bacterial growth. Temperature in the storage container is maintained

4 | Vaisala News 175 / 2 0 07 CA storage makes it possible to buy crisp, juicy apples year round.

Apple respiration: apples take in oxygen and generate carbon dioxide, water, and heat.

Storage Control Systems Inc’s CO2 scrubber called the Series II Smart Scrubber.

around 1°C, the lowest possible tempera- and the reduction of CO2 through the containing activated carbon. Activated ture before damage to tissue occurs. course of the storage period. Because of carbon is a porous adsorbent material, their responsibility to control the desired meaning that the carbon dioxide mole- Carefully designed process gas concentrations in the chambers, cules are attracted to and adhere to the The typical process for CA storage begins these analyzers are critical to the opera- surface of the carbon media. The activated by filling a storage chamber with apples. tion of the entire system. carbon gradually becomes saturated, so Some chambers are large enough to it is necessary to periodically purge the contain up to 400 tons of apples. The From bags of lime to more beds with fresh air to remove the CO2. refrigeration apparatus is then acti- sophisticated methods The unit is programmed to adsorb on vated to achieve the target temperature Years ago, chamber operators used one bed, while purging with fresh air on of 1°C. During cooling, the windows or hydrated lime to control the CO2 in the the other to allow for continuous scrub- other chamber openings are left open to fruit store. Bags of lime were loaded on bing. The Series II Smart Scrubber is prevent a possible collapse due to pres- pallets and placed into the store which also programmed with a “DeOx” cycle sure changes. absorbed all the CO2 that was emitted to minimize oxygen feedback to the CA When the desired storage tempera- from the apples, eventually leaving the room. ture is reached, the room is sealed with an store with no CO2. Lime (calcium oxide, The Series II Scrubber uses a program- airtight CA door. Once sealed, a nitrogen CaO) absorbs CO2 and in turn reacts mable logic controller (PLC) with a color generator is started to purge the O2 to form calcium carbonate (limestone, touchscreen interface to carry out its concentration in the chamber from 21% CaCO3). Once all the lime was converted control and sequencing functions. The (found in normal air) to approximately to calcium carbonate, the operator was PLC operator interface allows simple 3%. Once this level is reached the fruit forced to manually vent or flush the room programming of CO2 concentrations, will continue to reduce the O2 concen- with nitrogen to control the CO2 level. resulting in highly effective fresh fruit tration through the respiration process. Nitrogen generators require large, storage regimes. If the O2 concentration were to ever fall high-power air compressors that can be The Vaisala CARBOCAP® Carbon to zero the apples would suffer unwanted costly to run with continuous usage. A Dioxide Module GMM221 is used to and irreversible fermentation reactions carbon dioxide scrubber is a more effi- monitor the CO2 output from the beds, in the fruit. If O2 levels drop below the cient and affordable tool for removing which controls the switching of the safe concentration, outside air is added and controlling CO2 inside a fruit store. process from scrubbing to regenerating to the chamber to raise O2 concentration CO2 scrubbers not only remove CO2, or vice versa at the most efficient point. to the intended level. but also remove some volatile organic Also, a snapshot of the CO2 coming from In addition to generating CO2, the carbons (VOCs) and ethylene, allowing the room is taken at the beginning of the apples also generate ethylene gas which optimal storage of fruit. cycle using the GMM221. This informa- accelerates ripening. Increased levels tion is logged into the PLC, which uses of CO2 will halt the ethylene produc- Seriously smart CO2 scrubbers the readings to set the optimal scrub and tion and therefore slow the ripening Storage Control Systems, Inc. is a regeneration set points. process of apples dramatically. However, company that specializes in gas analyzers, The Vaisala carbon dioxide sensor if the CO2 concentration is too high it nitrogen generators and CO2 scrubbers is highly stable, very reliable, does not may terminate the life of the apple by for CA storage systems. Having been in require routine calibration and is able to destroying appearance, flavor, and nutri- the business for over 25 years, they are read gas concentration levels over several tional value. In order to maintain the CO2 one of the longest established CA compa- months to an accuracy of <0.5%. This is at the desired level, the excess CO2 must nies in the world. critically important for successful long- be removed from the air in the chamber. SCS supplies a unique CO2 scrubber term fruit storage and requires minimal Gas analyzers are used to monitor and called the Series II Smart Scrubber. This maintenance by the operator. n control the addition and removal of O2 scrubber consists of two cylindrical beds

175 / 2007 Vaisala News | 5 Ulla Mattila Application Manager Vaisala Helsinki, Finland and Penny Hickey Application Sales Engineer Vaisala Keep it cool Boston, MA, USA Measuring carbon dioxide in refrigeration applications

CO2, a widely used refrigerant in the early of various concentrations of CO2 on well as the plant room. Each room has 20th century, was largely replaced by the human health are summarized in Table a local visual alarm set to activate at chlorofluorocarbon (CFC) and hydro- 1. Unlike ammonia, it is impossible to 3,000 ppm and a second set-point at chlorofluorocarbon (HCFC) refriger- detect leakage of the colorless and odor- 5,000 ppm programmed into the control ants in the 1940s. The damaging effect less CO2 from the refrigeration system system supplied by John McDaniels at of the CFCs and HCFCs on the ozone without proper sensors. Computer Process Controls. Having layer became evident in the 1970s. These To ensure the safety of personnel in a separate programmable alarm point compounds are also effective greenhouse a CO2 refrigerated facility, CO2 trans- means we have been able to set the lower gases contributing to the climate change. mitters should be installed in every limit for the local alarm and know that Consequently, a gradual phasing out has human occupied space and as close to the operators cannot adjust the set- been taking place in order to replace potential leakage points as possible. The points or isolate the alarm.” these compounds in various applica- number of transmitters should be based tions. The Montreal Protocol was opened on risk assessment. Ventilation and air Vaisala sensors are for signatures in 1987 to phase out the flow should be considered when plan- accurate and durable ozone-depleting chemicals, including ning transmitter installations. Carbon Rob Whitehead lists the requirements for CFCs and HCFCs, resulting in nearly all dioxide is twice as heavy as air and sinks CO2 transmitters: “The leak detector has countries joining the effort to protect the and pools low to the ground, displacing to be sturdy, have a remote sensor and a ozone layer. Simultaneous re-inventing oxygen in the air. Therefore, appropriate display. It needs to be able to talk to the of natural refrigerants has taken place. installation locations for the transmitters control and alarm system.” The re-birth of CO2 refrigeration was initi- are at floor level. The Vaisala CARBOCAP® Carbon ated by the pioneering work of Gustav Dioxide Transmitters GMT221 and Lorentzen in the 1980s and his invention Safety and system GMT222 are especially designed for of the trans-critical CO2 heat cycle. integrity are key issues harsh and humid environments. The Many factors promote the use of CO2 McAlpine Hussmann Ltd. has experi- operating temperature range of the as a refrigerant. It is inexpensive and ence of integrating Vaisala CARBOCAP® GMT221 transmitter is specified as -20 energy-efficient. In addition, it has good Carbon Dioxide GMT220 Series Trans- to +60°C. The transmitters have been heat transfer properties and is compat- mitters as leak detectors in CO2 refrigera- tested in temperatures down to -40°C ible with most materials. The challenges tion applications. using both a constant low temperature related to process design, high oper- McAlpine Hussmann Ltd. provides and a rapid temperature gradient from ating pressures and downtime safety solutions for the display and refrigeration -40°C to +70°C. The temperature depen- issues can be overcome with modern needs of supermarkets and grocery stores dency has been modeled down to -30°C. technology. From an environmental throughout Australasia. Their product “The Vaisala system has allowed us the point of view, CO2 does not cause ozone range includes refrigerated and non-re- flexibility of mounting the detector units depletion and has lower global warming frigerated display merchandisers, refrig- outside the refrigerated rooms at suffi- potential than the traditional refriger- eration systems, evaporative condensers, cient height to avoid the risk of mechan- ants. As a result, CO2 refrigeration has heat exchange coils, beverage coolers ical damage,” says Rob Whitehead. found numerous applications in food and and walk-in coolers and freezers. They The Vaisala CARBOCAP® sensors are industrial processing, cold storages, food also offer installation, service and main- accurate and durable. They have excel- retail and transfer, and sports facilities. tenance and aftermarket service through lent stability in terms of time and temper- It is also emerging in car and residential their service organization. ature, which will reduce maintenance air-conditioning. “Safety and system integrity are key costs over the years. The Vaisala sensors issues,” says Rob Whitehead, Application enable reliable carbon dioxide detection Detecting leakage of Engineer from McAlpine Hussmann Ltd. for the wellbeing of people working in colorless and odorless gas in New Zealand. “Local codes state that carbon dioxide refrigerated spaces or CO2 is a non-toxic and non-flammable any refrigerated space open to public people enjoying an exciting ice hockey gas. However, it does not support life and access must have local leak detection and game in a carbon dioxide refrigerated ice exposure to elevated concentrations of alarms. We decided to go a step further stadium. n CO2 can induce a risk to life. The effects and alarm every refrigerated room as

6 | Vaisala News 175 / 2 0 07 Many factors promote the use of CO2 as a refrigerant.

Concentration Effect 350 – 450 ppm Typical atmosphere 600 – 800 ppm Acceptable indoor air quality 5000 ppm Average exposure limit over 8 hours 3 – 8% Increased respiration and headache above 10% Nausea, vomiting, unconsciousness above 20% Rapid unconsciousness, death Table 1: Effects of different concentrations of CO2 on human health.

175 / 2007 Vaisala News | 7 Mikko Laakso Product Line Manager Vaisala Helsinki, Finland

A perfect combination of old and new Vaisala CARBOCAP® carbon dioxide measurement technology celebrates ten years in business

Nondispersive Infrared (NDIR) gas published their most important article were launched. Christer Helenelund, sensing has been recognized as one of on what we today call the Fabry-Perot Product Line Manager for CARBOCAP® the most powerful tools for gas analysis Interferometer (FPI). Based on the products for eight years, looks back at the for decades. Over time, advances have interference of light refl ecting back and hectic moments before the launch: “At been made in NDIR gas sensing devices: forth between two mirror surfaces, the one point before the launch we observed infrared light sources, infrared fi lters, device acts as a bandpass fi lter permit- some stability problems and identifi ed sensor optics and sensing algorithms ting only a certain wavelength of light altogether 12 possible sources for drift to name but a few. Seldom, however, to pass through it. Th e fi rst devices were that had to be analyzed. It later turned has there been such a profoundly new large, weighed several tens of kilos, and out that not one of them was the correct and innovative method introduced to were used for accurate determination of one!” NDIR gas sensing as when the Vaisala lengths and wavelengths. CARBOCAP® carbon dioxide sensor was A good product keeps introduced in 1997. As great inventions From drawing boards getting better often are, it was a combination of the to product launch Th e sensor structure has evolved and tried and trusted with something totally Th e fi rst ideas on silicon micromachined improved signifi cantly from those days, new – combining NDIR gas sensing and optical fi lters were discussed at Vaisala but the Vaisala CARBOCAP® Carbon hundred-year-old optical principles with already in the very early 1990’s. “First Dioxide Transmitter GMD/W20 products silicon micromechanics. we were thinking of an optical pressure that were then launched are still going In 1897, exactly one hundred years sensor with a remote readout using fi bre strong and proving their robustness and before CARBOCAP® was invented, French optics,” recalls Ari Lehto, one of the tech- stability in HVAC installations around physicists Charles Fabry and Alfred Pérot nology pioneers and key fi gures behind the world. In ten years, the CARBOCAP® the CARBOCAP® technology, now the product family has grown towards more Professor of silicon technology at the and more demanding applications. Today Helsinki University of Technology. the CARBOCAP® technology is known as Th e technical ideas were combined the state-of-the-art NDIR technology in with the business intent of entering the a wealth of CO2 measurement applica- gas measurements market with propri- tions ranging from pharmaceutical CO2 etary technology, and the project gained incubators to ecological carbon cycle direction and momentum. Finally in 1997, research. after several years of intense technology We wish the lively ten-year-old all the development and countless cycles of trial best on its way to growing into an ener- and error, the fi rst CARBOCAP® products getic teenager! n 8 | Vaisala News 175 / 2 0 07 Maria Uusimaa Application Manager Vaisala Helsinki, Finland

Extend your measurement range

The upgraded CO2 probe goes “underground”

Vaisala CARBOCAP® Carbon Dioxide and measurements in lakes and even of the probe has not been wide enough Probe GMP343 has recently been oceans. Th e probe has also been used for all below-ground CO2 measurements upgraded with improved features espe- in boundary layer measurements with since in some soil types and conditions cially for ecological measurement appli- a tethered sonde as well as in an ecolog- the CO2 concentration can rise multi- cations: in addition to the slightly new ical measurement station application in fold from the ambient CO2 background appearance of the probe, the most the Helsinki Testbed. Furthermore, OEM concentration of 370 ppm. noticeable new feature is the extended customers manufacturing total organic The growing need for the below- measurement range, up to 2% CO2. Th e carbon (TOC) analyzers have found the ground soil respiration measure- low end of the measurement range, the GMP343 suitable for integration with ments has called for an extension of 0 – 1000 ppm range, also has improved their measurement equipment. the measurement range, whereas the linearity and temperature dependency. growing interest in atmospheric CO2 Both changes enable increasingly reliable Below-ground soil concentration measurements, such as and accurate ecological measurements. respiration measurements urban air CO2 measurements, encour- Th e GMP343 was launched three One of the most successful applications aged us to improve the probe’s perfor- years ago. Th e probe was designed for the for the GMP343 in the ecological segment mance in the ambient CO2 concentration ecological CO2 measurement segment. It has been a particular niche of soil respi- measurement range. is successful in a variety of research appli- ration measurements, where soil CO2 Th e upgraded GMP343 is calibrated cations, such as soil respiration measure- is measured below ground in a vertical at the factory at three new CO2 concen- ments, plant growth chamber control, profi le. However, the measurement range tration points, which adds up to a total

175 / 2007 Vaisala News | 9 Figure 1. The open path, diffusion aspirated model (left) and the flow through model (right) of the upgraded GMP343. of seven gas calibration points (0, 200, both the absorption and the reference 370, 600, 1000, 4000 ppm and 2%). The bandwidths, which eliminates the errors The GMP343 uses new temperature compensation is commonly present in NDIR sensors with the renowned applied to each probe individually, and two IR detectors. The true reference Vaisala CARBOCAP each upgraded probe is calibrated at measurement enables good stability of ® four temperature points (-30, 0, 25, and the sensor both in terms of time and measurement 50°C). temperature. It is worth emphasizing that the temperature stability also results technology. We know how to make in a good stability with flow, which is an reliable sensors important feature, especially in diffusion- The GMP343 uses the renowned Vaisala based sensors. CARBOCAP® measurement technology. The upgraded GMP343 comes as a The absorption of infrared (IR) light is diffusion-based or a flow through-based measured in this technology by using model (Figure 1) and features low power small silicon-based, electrically tunable consumption and small size compared to Fabry-Perot Interferometer (FPI) acting traditional CO2 equipment designed for as a tunable bandpass filter. The FPI is the ecological segment. The probe also continuously measuring not only the sustains harsh environments and can be CO2 absorption band but also a reference installed outdoors without complicated band. Because of this, a true reference protection or shelters. n measurement, and, therefore, a stable CO2 measurement can be obtained. Only a single IR detector is used for measuring

10 | Vaisala News 175 / 2 0 07 Ulla Mattila Application Manager Vaisala Helsinki, Finland A breath of fresh air

New CO2 transmitter for demand controlled ventilation

The Vaisala CARBOCAP® CO2 sensors transmitters provides years of stable CO2 for a pleasant environment. Problems have proven their accuracy and dura- measurements. arise when, in order to save energy, the bility during their ten-year presence on ventilation system is not used to bring in the market. They have an excellent long- New and improved sufficient amounts of fresh air. term stability, which decreases mainte- tools from Vaisala nance costs over the years. The new GMW115 Transmitter and Guidelines for indoor The superior performance of the GMM112 Module are both designed CO2 concentrations CARBOCAP® sensors largely results from especially for DCV (Demand Controlled The CO2 level can be used as an indicator the stable reference provided by the elec- Ventilation) applications with the CO2 for indoor human presence. A high CO2 trically tunable Fabry-Perot Interferom- measurement range of 0…2000 ppm. level is a sign of poor ventilation and eter (FPI). With the tunable FPI filter not The GMW115 Transmitter replaces the often an indication of other unpleasant only the CO2 absorption is measured, but GMW25/45 Transmitters, offering reli- odors in the air. Since in many buildings also a reference wavelength. This internal able and stable CO2 measurements for the ventilation need varies during the reference measurement compensates standard DVC needs (see long-term day, DCV is an economical way to ensure effectively for any changes in the optical stability data in Figure 1). good air quality. By controlling the venti- path, like light source intensity changes The GMM112 is a compact diffusion lation system using CO2 measurement, and contamination. This type of refer- aspirated module especially designed for good indoor air quality can be provided ence is a unique feature in the CO2 trans- OEM applications. The GMD/W20 series energy-efficiently. mitters on the HVAC market, separating transmitters are still available for applica- The limits for indoor CO2 levels differ CARBOCAP® products from competitors tions where wider measurement range or slightly in different countries, but for that have either no reference measure- optional outputs are required. example ASHRAE (American Society ment at all or indirect reference measure- of Heating, Refrigerating and Air Condi- ment based on assumed background CO2 Good indoor air quality tioning Engineers) recommends the level. is important CO2 levels not to exceed 700 ppm above Especially in applications with a Most of us spend 90 % of our time indoors. outdoor ambient levels. OSHA (U.S. round-the-clock occupancy (e.g. hospi- Consequently, good indoor air quality is Occupational Safety and Health Admin- tals, workplaces, residential buildings, important to our wellbeing. Every human istration) has set a limit for the CO2 homes for the elderly), the background being is a source of carbon dioxide, concentration in the workplace to 5000 CO2 level reference just doesn’t work. increasing the CO2 level in human occu- ppm for prolonged periods. n The true internal reference measure- pied spaces. Thus the introduction of ment of Vaisala CARBOCAP® CO2 fresh air by a ventilation system is needed Figure 1: Long-term stability of GMW115 transmitters.

450

) 400 m p

p 350 ( 2 300 CO

250 on i t 200 a r 150 GMW115 #1 e nt

c GMW115 #2 100 GMW115 #3 C on 50 GMW115 #4 0 0 1 2 3 4 5 6 7 8 Time (month)

175 / 2007 Vaisala News | 11 AGA oxygen production plant provides oxygen for the Kaukas pulp mill. Hannu Valo Mechanics Engineer and Maria Uusimaa Application Manager Vaisala Producing oxygen for some Helsinki, Finland serious “paperwork” Vaisala contributes to a trouble-free air separation process

The Vaisala SPECTRACAP® Oxygen At the Kaukas mill the OMT355 is used pulp bleaching and have thus contrib- Transmitter OMT355 is an analyzer- in an oxygen production facility managed uted to more environmentally friendly type instrument that can be used in a by the AGA Corporation. paper production. Th e oxygen bleaching variety of measurement applications. It Th e AGA Corporation is part of the process employs oxygen to remove lignin, has a measurement range of up to 100% Linde Group, the world’s leading gas which in the course of time shades the O2. Th e transmitter is used in O2 produc- producer. AGA’s main gas products paper product yellow. tion at the UPM-Kymmene Kaukas pulp are oxygen, nitrogen and argon, which Oxygen is produced from air at the mill in Finland. Th e oxygen used in pulp together generate half of the company’s AGA Kaukas site. Air is a gas mixture production can contribute to a more revenue. At the Kaukas site the AGA mainly composed of nitrogen (78%), environmentally friendly paper produc- oxygen production plant provides oxygen oxygen (21%) and argon (1%). Th ese gases tion process. for the pulp mill. can be produced from plain air with air Th e OMT355 oxygen transmitter is separation methods. Th ere are various an optical, tunable diode laser oxygen More environmentally methods for air separation, but at Kaukas analyzer for industrial gas measurements. friendly paper production oxygen is produced with a specifi c sepa- Its measurement range enables its use Th e Kaukas paper mill uses bleached ration method called the Pressure and in various gas manufacturing processes, sulfate pulp in its coated printing paper Vacuum Swing Adsorption (PVSA) such as in inert gas - typically nitrogen - products. Oxygen and ozone bleaching process. Th e raw materials required in manufacturing, or in oxygen production. have partly substituted chlorine in the process are air and electricity. Th e

12 | Vaisala News 175 / 2 0 07 oxygen manufacturing is mostly nitrogen. In PVSA processes both installation Th e two adsorbers, several cubic meters methods can be used. At the AGA Kaukas OMT355 in air separation each, are fi lled with synthetic zeolite site the installation was made at a Y junc- • 0 – 100% O2 measurement mineral acting as a molecular sieve or tion combining the two adsorbers with range fi lter. Th e gas content changes when trav- a very simple sample drawing system • Can be used in both N2 and O2 eling through the sieve. Th e oxygen mole- consisting of a 6 mm tube, a rotameter manufacturing cules pass through the sieve with minor and a Vaisala-supplied sampling cell. • Typical applications include restriction, while nitrogen molecules get “Th e robustness of the OMT355 would inert gas manufacturing or trapped in the zeolite’s structure. In other easily have enabled direct (in-situ) instal- oxygen production words, oxygen is enriched and nitrogen lation to the process, which is far too • Easy installation, long-term is adsorbed. demanding for other products, but the stability, ease of calibration When saturated with nitrogen, the critical maintenance schedule at the check adsorber performance is no longer pulp mill did not allow it this time,” says • Fast response time, insensi- suffi cient. Excess nitrogen needs to be Heimo Märkälä, who is responsible for tive to process fl ow rate and removed with fi lter regeneration. Th e plant instrumentation and automation small variations in process regeneration is accomplished by utilizing maintenance at AGA production sites. pressure a vacuum to draw the nitrogen molecules “During the test period it became evident • No complicated sampling out of the fi lter media. A typical setup that the pressure and vibration toler- systems required contains two tanks fi lled with zeolite. ances of the OMT355 are excellent.” One tank is used to adsorb nitrogen while the other is being regenerated. Th e cycle Durable tool for preventive PVSA method is especially suitable for time of the process is typically less than maintenance small to medium-sized production facili- one minute - that is, one tank fi lters air In a PVSA process, the oxygen content of ties when the required oxygen purity is for a minute followed by one-minute the produced gas changes as the zeolite signifi cantly lower than 100% O2. regeneration. degrades or there is a malfunction in the valve system. Currently, the adsorber Separating air with Simple installation directly temperatures and pressures are moni- the PVSA method into the process possible tored by the control system, but the reac- Th e PVSA method is based on pressur- Th e Vaisala OMT355 with in-line or tion time of these measurements is slow izing and depressurizing a container with sample cell installation options is highly and cannot predict mechanical failure a selective molecular sieve. Th e condi- insensitive to variations in process gas before it is too late. tions inside the process vary as oxygen velocity, and slightly changing pressure “With the OMT355 we can see potential is separated from air: pressure is needed within the operating pressure range only problems before they cause serious degra- to push air through the fi lter; vacuum has a minor eff ect on the measurement. dation in the process performance and is required in the regeneration of the Th ese special properties of the instru- can use that information for preventive system and removal of nitrogen from the ment enable simple installation directly maintenance,” says Heimo Märkälä. “I can molecular sieve. into the process (in-line) or installation see potential for this product in preventive In the PVSA process, ambient air is with a simple sampling system requiring maintenance, and for product O2 measure- pressurized with an air compressor. Th e minimal sample conditioning, also ment - it is easy to install, has excellent compressed air is then fed to the adsorbers ensuring a fast response time for the environmental tolerance and a quick to remove the unwanted content, which in measurement. response time at very reasonable cost.” n

Heimo Märkälä demonstrating the OMT355 installed at the AGA Schematic diagram of the pressure and vacuum swing adsorption Kaukas plant. (PVSA) oxygen manufacturing process.

175 / 2007 Vaisala News | 13 Paul Nieberding Applications Engineer Fondriest Environmental Beavercreek, OH, USA

Clean beach, happy swimmers Vaisala at the Presque Isle State Park

The new Tom Ridge Environmental Center at Presque Isle. The Consortium Model for the determination of E. coli Center (TREC) is located at the entrance is a collaborative, non-profit organization contamination on the beaches of Presque to Presque Isle State Park in Erie, Penn- that focuses on and coordinates educa- Isle. It is part of a complex system that sylvania. TREC is open year-round, tional and research projects for Lake Erie provides information for making deci- offering visitors an insight to what they and the upper Ohio River Basin. sions regarding beach advisories and/or can expect to experience at Presque Isle The Consortium’s objective is to have restrictions to swimming. State Park and the surrounding Great all branches of science working collabor- Both the Vaisala Weather Transmitter Lakes Region. atively in order to share expertise, equip- WXT510 and the pyranometer feature a TREC also serves as a center for ment and ideas while sharing researchers plug-and-play interface to NexSens’ real- research, contributing to conservation and students as well. One of the Consor- time data logging systems. Furthermore, efforts and promoting environmental tium’s most recent educational and the complete data logging and sensor awareness, helping to preserve the unpar- research tools is a Vaisala Weather Trans- system package is conveniently mounted alleled beauty of Presque Isle, the site of mitter WXT510 network with NexSens to a 2” mast. Pennsylvania’s only lakeshore. Technology real-time radio telemetry. At user-specified intervals throughout The Regional Science Consortium Systems are installed on the TREC Tower the day, weather data is logged into the is one of the many educational and and near the Lake Erie shores at Presque NexSens 4100-iSIC data loggers and sent research organizations establishing resi- Isle State Park. via radio telemetry to a radio base station dence in the Tom Ridge Environmental within the Center. There, iChart software The monitoring system collects the weather data and automati- Two site locations were selected within cally posts it to NexSens’ web datacenter. the Presque Isle State Park to monitor This allows virtually unlimited access weather. The first weather station loca- to the weather data for Consortium tion was selected near Presque Isle’s Lake members throughout the United States Erie shoreline, while a second weather to use the data in their research or to station location was selected on top of remotely determine weather conditions the TREC’s 75-foot tall glass tower. for planning sampling trips at Presque Researchers at the Consortium Isle. selected the Vaisala equipment to measure six important weather param- Increasing the amount eters at two locations in Presque Isle of real-time data State Park. The WXT510 simultaneously Looking ahead, the Regional Science measures wind speed and direction, Consortium is considering adding other liquid precipitation, barometric pres- real-time environmental monitoring sure, temperature, and relative humidity. venues that will complement the weather Complementing the Vaisala weather data logging system, including buoy- sensor is a global solar radiation sensor. based water quality monitoring devices on Lake Erie. n Safe swimming Nicole Phinney, an intern at the Regional Science Consortium, pictured The weather data collected by the Further information: at one of the weather station sites. WXT510 is used to augment a Predictive www.RegSciConsort.com

14 | Vaisala News 175 / 2 0 07 John Johnston Manager, WeatherHawk Division Campbell Scientiﬁ c, Inc. Logan, UT, USA

Watch your home like a hawk WeatherHawk Series 500 Weather Station WeatherHawk home automation with the Vaisala Weather Transmitter WXT510. solutions incorporate Vaisala’s weather measurement know-how

WeatherHawk, a division of Campbell modern self-contained design, and excel- created a market for high specifi cation Scientifi c, Inc., identifi ed the high value lent support provided by Vaisala. weather stations on high value homes. home automation weather station If a homeowner wants to control home market in 2003 for its standard Weather- What is a home automation features/functions, or make local plans Hawk fully self-contained meteorological weather station? based on weather, they cannot rely on station. By 2005, it became apparent that A microclimate is very simply the climate a regional weather report, so many are the best product for this application was of a specifi c place within the climate of using a home weather station for their a product that did not look like a tradi- a larger area. Microclimates can be very microclimate information. tional weather station. Based on that diff erent from the climate of the overall Home automation, as a technology reality, WeatherHawk began the design larger area. Th is fact is evident when you products market, has evolved over the of its new WeatherHawk 500 Series hear the weather report for a large city past 15 years from remote lighting and low profi le home automation weather and note that the weather condition in audio/visual controls, to very sophisti- stations and selected the Vaisala Weather the countryside is diff erent than it is in cated total environment home control Transmitter WXT510 as the primary the city. systems. Th e level of integration now sensor module. Th e selection of the It is this diff erence in the regional includes both indoor and outdoor sensors WXT510 was based on its specifi cations, and microclimate conditions that has and controllers for virtually any function

175 / 2007 Vaisala News | 15 you can imagine in a home. Th e market also has unique product and application characteristics that make it a diffi - WeatherHawk weather stations integrated with a cult long cycle sales/support challenge. home control system enable automatic responses to: Although it is global in nature, the home • changes in solar radiation automation market is strongest in the - window coverings open or close to protect expensive carpets United States where over 40,000 homes and furnishings from the eff ects of UV, and the activity provides a valued at over US $1 million were built perception that the home is occupied in 2004. Of that number, about 15% have - sidewalk lighting automatically turns on for safety and security a high level of home automation and a • changes in outdoor air temperature signifi cant percentage of those are candi- - walkway and driveway heating melts snow and ice for safety dates for a home weather station. - optimizes pool and spa heating system functions At a home, a weather station measures • changes in wind velocity and direction the ambient conditions that create a - controls sprinklers and fountains to eliminate overspray homeowners microclimate. With that - closes storm shutters to protect windows from wind blown debris information and a connection to the (hurricanes, typhoons and tornados) Internet, various home automation • daily calculation of evapotranspiration for use by an irrigation controller systems can control home features/func- - optimizes landscape irrigation to save water tions in a near immediate response to changes in the microclimate. In addition, any one of several independent weather services can use home weather station data to better predict the weather at that home for fi ve-ten days into the future To gain the most value from a home weather to facilitate homeowner recreational station a home owner needs a system that will: planning. • seamlessly connect to their chosen home control system For homeowners that travel, or those • connect to the Internet using software on their home control system, or that have more than one residence, their PC current weather conditions at any of their • have minimal maintenance and no user calibration requirements homes can be automatically updated on • have a range of mounting options their personal websites for access over • look good to meet the architectural compliance requirements of many the Internet from anywhere in the world. neighborhoods. Th is enables them to make recreational and travel decisions to homes in remote locations that may not have reliable weather information. The Vaisala Weather Transmitter WXT510 enabled WeatherHawk to design a low profi le, visually pleasing, yet rugged and reliable, fully self-contained weather station that meets the aesthetic requirements of all but the toughest architectural restrictions. n

WeatherHawk 511 Home Automation Weather Station.

16 | Vaisala News 175 / 2 0 07 UPM’s WISA veneers Liisa Åström bring the natural beauty Application Manager of wood to life. Vaisala Helsinki, Finland

Bringing out the beauty of wood Veneer drying with humidity control

One of the world’s leading forest product groups, UPM, produces among other things special veneers that are marketed under the WISA brand. At Lohja Veneer mill in Finland, some 14,000 m3 of veneer made from birch and pine is produced annually for markets across the world. The main end use applications of this beautiful material are furniture, doors and interior decorations of different kinds. In the veneer drying process, the plant counts on Vaisala’s dewpoint transmitters that can take the heat. Veneer refers to thin slices of wood, typically between 0.5 and 3.0 mm. Veneer is spliced into sheets, and can then be glued and pressed onto core panels of different materials to obtain furniture, doors and interior decorations. The deco- rative end uses set high demands on the control of the veneer production process. The drying process plays a key role as accurate dewpoint control ensures that the best quality veneer is obtained at all times. Veneer making step-by-step In veneer production, one of the first steps is cooking the log. Next, the wet log is flat sliced, much like salami is sliced at the delicatessen. Veneer is fed into a press dryer, where it travels between two conveyors through the high temperature dryer. In modern dryers, separate zones allow tight control and adjustment of the internal temperature and humidity of the dryer. The veneer exits the dyer, sheet by sheet, ready to be graded, cut into matching size sheets and bundled.

175 / 2007 Vaisala News | 17 Th e veneer sheets are passed through the an important role. Th e veneer must be dryer and collected by operators at the end of the line. dried well for it to be fl at, fl exible and suitable for further processing. Our customers continue to splice the veneer A state-of-the-art mill into sheets, and to succeed in that, the Sami Janhunen works as a Plant Engineer veneer moisture content must be at a at UPM’s Veneer Mill in Lohja, Finland. suitable and even level. Too dry veneer His responsibilities include maintaining may cause problems in splicing because and developing the production equip- it becomes brittle and may break. From ment at the plant. A major project was the veneer manufacturer’s point of view, realized roughly a year ago, when a large over-drying is uneconomical in terms of part of the equipment was modernized energy and capacity losses and decline in to meet the highest quality, capacity veneer quality.” Th e Vaisala DRYCAP Dewpoint Transmitter DMT346, as its predecessor® DMP246, can and work safety requirements. Th is was Direct installation with be directly installed into temperatures up to done in co-operation with Raute, the 350 °C (662 °F). world market leader as a supplier of mill- no sampling systems wide projects to the veneer-based wood Th e humidity inside a dryer is measured UPM Special Veneer Plant Engineer Sami product industry. At this time, the equip- with Vaisala DRYCAP® Dewpoint Trans- Janhunen (left) together with Vaisala Sales ment supplier Raute chose to include mitters DMP246, which are directly Engineer Jukka Kalliokoski. Vaisala DRYCAP® Dewpoint Transmit- installed into diff erent zones of the dryer. ters DMP246 as humidity control instru- No complicated sampling systems are ments for the dryer. Th is product has needed. Th e measurement information is since been replaced by the DMT346. connected to the operating system of the Previously, there was no measure- dryer, which connects all relevant infor- ment of humidity in the dryer at Lohja mation needed to control the dryer oper- mill, and running the process depended ation. Th e data of this PLC-based system on the operators’ good experience and may be accessed from remote monitors craftsmanship. Still today, professional at the operator’s location and changes to skills are important, and there is no set operating procedures are made on touch of parameters as precise as the human screens. eye to evaluate the appearance of veneer. Janhunen says the Vaisala equipment However, on-line measurement data meets their expectations well: “Th e units gives a whole new basis for controlling follow the process changes in a satisfying the process. way. Th ey play their part in the plant upgrade that has been positive for us in Quality through every way.” n dewpoint control Janhunen explains: “Quality is our main driver, and there the drying process has

18 | Vaisala News 175 / 2 0 07 Vaisala DRYCAP® Jan Grönblad products include a Product Line Manager selection of instru- Vaisala ments for ﬁ xed Helsinki, Finland installations and portable use.

Vaisala DRYCAP® key features: • Dewpoint measurement at low dewpoints • Excellent long-term stability • Fast response time • Recovers from saturation

Vaisala engineers a solution Vaisala DRYCAP® technology celebrates 10 years of happy customers

Th e Vaisala DRYCAP® technology was accuracy (even up to ±0.1 °C Td), but only with a wide variety of options, including developed according to customer needs if regularly maintained, typically daily. display, alarm and datalogging features. to measure low humidity with reliable technology. Customer problems with Superior Vaisala Flexible tool for industrial low humidity measurements, i.e. low measurement performance applications dewpoint measurements, related to poor With the new technology invented at Another important feature of the accuracy. Vaisala professionals were able Vaisala, all the problems of the old tech- DRYCAP® sensor technology is that it to solve the challenges. nologies were solved. Th e DRYCAP® tech- works extremely well as a portable tool, nology is based on a thin-fi lm polymer where the sensor is typically stored in Old technologies sensor. Th e polymer sensor is known to ambient air and used only briefl y to unsatisfactory be a very stable and reliable technology. measure very dry gas or air. Th anks Th ere were some clear reasons why the Th e D R Y C AP ® technology also applies to DRYCAP® performance, the sensor then existing technologies could not off er autocalibration, a patented key feature adapts to dry conditions very quickly. better performance. Th e traditional rela- that eliminates the sensor drifting at the Vaisala DRYCAP® dewpoint sensor tive humidity instruments that were dry end and allows dewpoint accuracy in technology is used in industrial applica- successfully used for higher humidity the long-term. Th is technology combina- tions where the humidity of a gas, typically measurements, typically from ambient tion off ers performance that fulfi lls the air, is very low. Typical applications are in levels up to saturation, were not accu- market requirements, is easy-to-use, is compressed air or the plastic molding rate enough in very low humidity, where cost-eff ective and has a very low need for industry or in dry storage where the the relative humidity is approaching maintenance. humidity is low (below 10%RH). A special 0%RH. In terms of dewpoint, this means During the past 10 years a wide product model for extreme temperatures up to dewpoint temperatures below -10 °C. range has been built up utilizing the +350 °C is also available for high-temper- Second, the typical technology that superior DRYCAP® measurement perfor- ature drying processes. Th is shows how was used for low humidity measure- mance. Today, the technology is avail- fl exible and suitable the technology is for ments was an Aluminium Oxide sensor able from a small-size low-cost dewpoint industrial dewpoint measurements. n that was sensitive enough down to very transmitter to a dewpoint transmitter low dewpoints (typically -70 to -80 °C Td). However, it was also sensitive to drift, which meant it required calibrating several times per year to keep the ±2 °C ® Vaisala DRYCAP ® Vaisala HUMICAP Td accuracy. Continuous calibration was costly and diffi cult. Th e third option was to use an analyzer Low 0 °C / 32 °F high type of instrument with a purchase price ten times that of a dewpoint transmitter. Dewpoint A typical example of this is a condensa- Vaisala DRYCAP® is one of the most reliable dewpoint measurement technologies for low tion hygrometer that can off er very high dewpoint measurements and Vaisala HUMICAP® for high dewpoint measurements.

175 / 2007 Vaisala News | 19 Cool down, the environmental way AZEVAP’s evaporative cooling technology with a Vaisala touch

20 | Vaisala News 175 / 2 0 07 Larry Kammerzell Managing Principal With today’s growing focus on global enough water to the media to makeup AZEVAP warming and the need to reduce energy for cooling evaporation and achieve Phoenix, AZ, USA consumption, evaporative cooling needs the desired cycles of concentration in to be revisited as an important cooling the discharge water. This is a dramatic alternative for buildings, industrial facili- change from the conventional recircu- ties, and gas turbine inlet air. An evapora- lating coolers which bath the media tive cooler uses as little as 1/8th the power with water pumped from a sump. At an of a traditional cooler or chiller system, average application rate greater than 2.5 yet industry has been backing away from times the evaporation rate, a conven- the use of this cooling method due to tional cooler often has water entrain- significant disadvantages of legacy tech- ment issues at lower air velocities and nology. Among the problems are: increased salinity of the water leading to • Reduced cooling effectiveness as an increase in the rate of media scaling. the wet bulb and relative humidity increase High efficiency even • High rate of media scaling and the after several years associated need for frequent replace- Published papers on cooling tower media ment of the media and experience with recirculating coolers • Reliability of the water level control using 12” media, show cooler evaporative system with associated conse- efficiency degrading relatively quickly quences of flooding and high over the first couple of months of opera- maintenance tion from a high of ~ 80% to less than • Water entrainment and corrosion of 70%. AZFlow® coolers have a demon- cooler components, ductwork, and strated ability to operate scale free and facility to achieve and maintain efficiencies of • Stagnant water and associated mold 85% to 90% even after several years of and fungus health issues operational service without changing or • High water usage rates cleaning the media. • Short cooler life As the relative humidity and wet bulb temperature rise, the theoretical amount AZEVAP, LLC has developed a new and of cooling that can be achieved by evap- innovative approach utilizing advanced oration decreases. Poor efficiencies in technology that addresses these tradi- conventional coolers further reduce the tional disadvantages. achieved cooling. The high efficiency of An evaporative cooler uses At the heart of the AZEVAP tech- the AZFlow® coolers means they are able as little as 1/8th the power nology is the AZFlow® water distribution to extend their effectiveness under these and metering system. This non-circu- adverse conditions, that is, the extra of a traditional cooler. lating system determines and applies just several degrees of cooling provided 

175 / 2007 Vaisala News | 21 by the AZFlow® system often achieves the AZFlow® Metal desired cooling objective. Building Install: Th is Th is high effi ciency also facilitates the through-the-wall installation was adaptation of the cooler into an eff ective designed to position energy recycle, indirect, and two stage the cooler in an ideal cooler confi gurations with the addition location for building of an air to air heat exchanger. AZEVAP air fl ow while mini- has married a patent pending air to air mizing the required support structure. heat exchanger design with the AZFlow® cooler to arrive at confi gurations that yield cool temperatures even under adverse ambient conditions. With this, the historic drawbacks to the use of evaporative cooling have been addressed. Save water Th e A Z F l o w ® metered water application system facilitates the elimination of the standing water sumps, recirculating pumps, and water makeup fl oat valve reliable and accurate relative humidity a web-based human-machine interface. which are the source of several of the and temperature measurements. After Th is interface allows: viewing the full set defi ciencies listed above. Th e AZFlow® careful evaluation of humidity sensing of system input parameters and resulting metered water application system saves technologies and manufacturers, the cooler performance, setting and acknowl- water by both reducing the number Vaisala HUMICAP® Humidity and edging alarms, and establishing and of coolers required and reducing the Temperature Transmitter Series HMT100 setting fail safe contingency actions. amount of water discharged as bleed was selected as the measurement and After deploying its AZFLOW® coolers water to limit or avoid scale formation. control device. within its own facilities and realizing Th e AZFlow® coolers discharge less than Th e measured air temperature and tremendous productivity, energy, and 10% of the water discharged as bleed relative humidity along with airfl ow data water savings, AZEVAP has installed water by other coolers. With no stag- are gathered and communicated with coolers in commercial and government nant water and only fresh chlorinated an I/O processor to a proprietary algo- facilities. An early version of the AZFlow® water used to wet the media, the health rithm in a Linux-based controller. Th is cooler installed at the landmark Bank of issues of stagnant water and growth of algorithm correlates the instantaneous America offi ce building in downtown mold and fungus are greatly reduced or water evaporation rate and the water Phoenix in 2003 paid for itself in savings eliminated. application rate and delivers the required in a little more than two months. n volume of water across the cooling pad Leadership in Energy and such that the pad never gets too wet or Environmental Design dry. Th e system accomplishes this by Th e building design and construction determining the on and off times of the industry has instituted the LEED program water application valve in order to keep (Leadership in Energy and Environmental the pad saturated. Design) as a way to gauge how eff ective a building is in supporting energy and Energy-saving pays off About AZEVAP LLC water conservation and other environ- Th e A Z F l o w cooler came about by ® Founded in 2001 to fi ll a need for mental sustainability. LEED’S points are designing a low fl ow water distribution evaporative coolers manufactured awarded for innovation, water saving, system and taking advantage of advance- as industrial process equipment, energy saving, and elimination of CFC ments in control system technology and AZEVAP’s founders and engi- and chemical usage. AZEVAP’s AZFlow hardware. In particular, today’s tech- ® neers Larry and Don Kammerzell coolers renew the potential for the use of nology enables the sensing of critical reviewed the history of evapo- evaporative coolers throughout industry parameters that impact the evapora- rative cooling and looked at the to achieve facility cooling objectives while tion rate. It also allows the program- fundamental problems associated saving energy, saving water, and reducing ming of the sophisticated algorithm that with the process. In developing the greenhouse gas emissions. Th e AZFlow accounts for these parameters and their ® AZFLOW cooling technology they coolers provide a means of capturing impact on the water evaporation rate combined a number of engineering a number of these points on new and into a stand alone micro processor and disciplines to solve the problems conversion building projects supporting controller that meters the correct volume that have limited the eff ectiveness higher levels of LEED certifi cation. of water onto the media. Th is was accom- of evaporative cooling. plished using a patented water distribu- Maximum benefi ts with tion system with an embedded Opto 22 Further information Vaisala measurements SNAP control system. www.azevap.com. In order to achieve the maximum benefi ts All cooler system control processes of the AZFlow® system, it is critical to have and acquired data are accessible through 22 | Vaisala News 175 / 2 0 07 Simo Ikonen Project Manager and Timo Ranta-aho Product Line Manager Vaisala Helsinki, Finland

Coping even with chemical interference New generation Vaisala HUMICAP® relative humidity sensor

In most humidity measurement appli- the migration of adverse chemicals or cations, the sensors are also exposed to completely prevents them from entering chemicals other than water vapor. Vapor- the active polymer layer. Th e chemical ized chemicals can diff use into the sensor resistant active polymer and the struc- and cause disturbances in the measure- ture of the capacitive sensor further ments. Such vapors are present in most contribute to the stability of the sensor. In environments, even in normal offi ce air. contrast to earlier sensor versions devel- Chemical vapors are also inherent in many oped to withstand demanding chemical industrial applications. For example air environments, these improvements have pollutants (NOx, SO2, etc.), disinfectants been obtained without compromising and diff erent organic solvents are often the other key properties of the sensor present in ambient air. As the responses such as high humidity stability, sensitivity to some gases and vapors are very slow, and hysteresis. in many cases several weeks or months, the eff ects are often described as “drift” or Field tests show high stability “aging” of the sensor and not as chemical Th e new Vaisala HUMICAP® sensor has interference. been tested both in laboratory conditions Th e chemical interference or drift can as well as in typical humidity sensor appli- be dealt with by setting the calibration cations¹. Th e tested humidity sensors interval according to the conditions or show signifi cantly lower measurement by improving the sensor’s ability to with- error in most of the test environments stand chemicals. In some cases heating compared to the reference sensors. Th e the sensor can either remove a chem- sensors perform better both in laboratory ical from the active polymer or prevent high chemical concentration tests as well entry. as in long-term fi eld stability tests. Th e results from the experiments show that Chemical resistant polymer the new structure and the polymer make and special new structure the sensor highly resistant to chemical Vaisala has introduced a new generation interference and therefore provide an Vaisala HUMICAP® relative humidity improved long-term stability for the rela- sensor, the HUMICAP®180R. Th is new tive humidity measurement. type of capacitive humidity sensor has been developed especially to cope with ¹ Ikonen S., Stormbom L., Ranta-aho T., chemical interference. Th e resistance to Chemical Interference Test Results of a chemical interference has been achieved Novel Humidity Sensor, 5th International Symposium on Humidity and Moisture – by developing a new type of chemical ISHM 2006, Rio de Janeiro, Brazil (2006) resistant polymer and a special new structure. Th e structure slows down

175 / 2007 Vaisala News | 23 Poor oil quality can lead to low dielectric strength and even failure.

Colin Feely Plant Maintenance Engineer Powercor Ltd Melbourne, Australia Detect moisture in oil Transformer moisture monitoring and dehydration

Powercor Australia is Victoria’s largest structures, the moisture quickly recovers. 2. T - temperature of the oil in degrees electricity distributor. Powercor has been Moisture monitoring provides a way of Celsius. running a program of on-line moisture tracking this recovery, and on-line drying monitoring on transformers using both provides a way of managing the moisture The probes also have an optional inbuilt permanently installed and portable mois- in oil so that the oil dielectric margin is algorithm which provides an output ture in oil probes, including the Vaisala maintained. in ppm. New oil formula is the factory HUMICAP® Moisture Meter MM70. default, and others can be programmed Poor oil quality can lead to low dielec- Moisture in oil measurement if known. In general, ppm values from tric strength and even failure. Oil treat- The moisture probes measure two the probes are lower than those from ment or replacement can address most quantities: Karl Fischer (KF) tests to determine oil quality issues but in the case of mois- 1. Aw - water activity, a relative satura- the water content of oil samples. This is ture which is held in the paper insulation tion of “active” dissolved moisture, a possibly due to bound water in particles of the windings and windings support fraction from 0 to 1. being captured by the Karl Fisher test.

24 | Vaisala News 175 / 2 0 07 Th e Karl Fisher moisture relative satu- Figure 1. ration results are defi ned as “Rs” in the 160 following. All transformers referred to BOTTOM OIL TEMP deg C NAMEPLATE RATING MOISTURE MONITOR ppm here are 66/22kv core form. (10 MVA) 140 22KV R PH AMPS/2 Moisture monitoring with 120 permanent probes Twelve Powercor transformers have 100 been fitted with permanent probes. Each provides two analogue outputs 80 to the Supervisory Control And Data 60 Acquisition (SCADA) system, ppm and temperature. Th e transformers selected 40 for monitoring were those with known oil quality issues, in general fairly old 20 and in some cases heavily loaded. Most 14.12.05 3.1.06 have been subject to oil regeneration or 0 1 21 41 61 81 101 121 141 161 181 201 221 241 261 281 301 321 341 361 381 401 421 441 replacement in recent times. Th e preferred location for the probe Figure 2. where transformers have detached radiator banks is the lower drain valve of the return oil line from the radiator to the main tank. Th is puts the probe in the oil fl ow from the thermo-siphon of the transformer. Where radiator banks are not detached, the chosen location was one of the lower radiator drain valves for similar reasons. Th e probes have a sliding type seal, which means they can be very simply installed through the drain valve with no outages required.

Figure 1: moisture variation, 10 MVA ONAN transformer. Figure 1 of the 10 MVA ONAN transformer demonstrates the eff ect of a load increase and a hot day. Note how moisture peaked at 60 ppm and did not recover for several days. Th e last KF moisture level from oil sampling was 30 ppm. A sustained high load during hot weather Figure 3. on this unit could lead to excessive moisture and a consequently low dielectric margin. On-line monitoring has shown that this unit is a good candidate for dehydration.

Figure 2: moisture comparison example (SCADA) - Scale is in ppm. Permanent SCADA connection enables comparisons to be made between sister units sharing the same load and conditions. Th e transformer showing the least moisture levels was subject to an oven dry out some fi ve years before.

Figure 3: moisture recovery following new oil retrofi ll. Scale is in ppm/deg C. In fi gure 3, a 20 MVA ONAF transformer, oil volume 17000 liters, oil change was completed on October 28th, 2005 and

175 / 2007 Vaisala News | 25 Figure 4. Figure 5.

ppm H2O °C ppm H2O °C 100 0,20 20 100 0,8 40

0,7 35 80 80 0,15 15 0,6 30 0,5 60 60

0,10 10 0,4 25

40 40 0,3 20 0,05 5 0,2 20 20 15 0,1

0 0,00 0 0 0,0 10 05-07-20 05-07-21 05-07-22 05-07-23 05-07-24 05-07-25 05-07-26 05-10-25 05-10-29 05-11-01 05-11-05 05-11-09

H2O, ppm H2O °C H2O, ppm H2O °C

Figure 6. Figure 7.

L2 DATA RAD PROBE TEMP 90 RAD PROBE MOISTURE ppm 0.500 250 45

Aw Aw Inlet Aw Outlet 24 per. Mov. Avg. (Aw) 0.450 40 80 Inlet Temp

0.400 200 35 70 0.350 30 60 0.300 150 25

50 0.250

20 0.200 100 40 15 0.150 30 10 0.100 50

20 0.050 5 21.12.04 22.9.05 10 0.000 0 0 1 241 481 721 961 1201 1441 1681 1921 2161 2401 2641 2881 3121 3361 3601 3841 4081 4321 4561 4801 5041 5281 5521 5761 6001 6241 6481 1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331 342 353 the contractor sampled the oil at 11 ppm had been oven dried out in the recent past. the oil through fi lter cartridges containing (KF). Within a few days the probe data A portable probe was quickly installed the molecular sieve material. Th ey are revealed that moisture levels had recov- and the data showed low moisture levels. fi tted with a single moisture probe, which ered and ranged from 16 to 37 ppm. A second oil sample confi rmed this - KF can monitor either incoming or outgoing of 9 ppm @ 15C (Rs =0.2) Dielectric = 82 oil. Th is is determined by the position of a Portable probes kV. Th e initial oil sample was probably bypass valve. When the outlet oil moisture Portable probes have also become avail- contaminated. equals (or exceeds) the inlet oil moisture, able, and Powercor has obtained three of the fi lter cartridges may have reached these from Vaisala. So far, they have been Figure 5: dramatic saturation, indicating that they should used on 20 transformers. Th ese probes reduction in moisture. be replaced. Each cartridge can theoreti- have a battery power supply and enough Figure 5 is from a 10/18 MVA ONAF trans- cally hold one liter of water and there are memory to store data at hourly reading former. Th e reduction in moisture coin- four cartridges per dryer. Th e cartridges intervals for about 30 days, which is cided with the commissioning of a new are quite expensive and at present there about the life of the battery. Once again, transformer at the station, which reduced are no recycling options available. the locations chosen are generally radi- the load signifi cantly on this unit. Th ese units are designed to take inlet ator drain valves to ensure a fl ow of oil In summary, the portable probes are oil from the main tank at the bottom, and past the probe. Th ese portable probes providing a very convenient and cost-ef- return oil to the conservator. Th is design allow fl exibility in that a large number of fective means to monitor any transformer has the advantage of avoiding any Buch- sites can be monitored. A probe can be which has valves in the appropriate loca- holz Relay (sudden pressure relay) issues installed and programmed to log data in tions. Transformers without such fi ttings should air get into the system. It has the a few minutes. A return visit to the site is could also be fi tted with probes in the disadvantage of exposing the newly dried required to download the data, clear the main tank drain or sampling valves. oil to the conservator head space. In memory for the next logging cycle and However, without a fl ow of oil over the Powercor’s case, this head space is open recharge the battery if required. probe, the results may be inaccurate or to the atmosphere. Th ese dryers have unrepresentative of the general oil mass. been used on nine transformers to date Figure 4: low moisture and a summary of the results follows. -66KV regulator. Dry outs with molecular In fi gure 4, an oil sample showed unex- sieve units Table 1: molecular sieve dryer pectedly high moisture and low dielectric, Powercor has two molecular sieve on-line results of some transformers KF of 43 ppm @ 22 C (Rs =0.7) Dielectric = dryers. Th ese units are trolley-mounted Please note: Oil parameters are from oil 36 kV. Th is was unexpected since the unit and remove moisture by simply pumping samples (i.e. KF and dielectric breakdown

26 | Vaisala News 175 / 2 0 07 tests) with the exception of the “S3” and Table 1. “L2” later oil parameters, which are from probes. Estimated Pre dry Dry removed Post dry Later oil Th e estimated removed moisture is Unit out oil Date on Date off hrs moisture out oil parameters based on the number of cartridge replace- C2 5 MVA 28ppm 30.7.04 17.8.04 386 1.5 liters 18ppm 20ppm ments and the moisture readings from the ONAF 25c(.41Rs) 20c(.32Rs) 24c(.31Rs) dryer inlet and outlet. Although the fi lter 11000 liters 22kv 58kv 55kv 8 months later cartridges have a rated capacity of one C3 5 MVA 41ppm 30.7.04 8.11.04 1039 4.2 liters 20ppm 31ppm liter, it was felt that, as moisture content ONAF 25c(.60Rs) 29c(.25Rs) 26c(.44Rs) reduced, they would stop removing mois- 15080 liters 24kv 73kv 55kv ture at less than that. In order to prove 6 months later this, weighing canisters were made up, S3 10/13 MVA 31ppm 6.12.04 21.6.05 1039 8.0 liters 13ppm 80 ppm peak, normal ONAF 23c(.49Rs) 22c(.22Rs) range 25-40 ppm and cartridges were weighed submersed 14800 liters 22kv 80 kv from SCADA- in oil when new and again when “full”. 6 months later Th e resultant average weight increase L2 10/13 MVA 41ppm 8.12.04 21.9.05 2563 14.0 liters 10ppm 17-27 ppm from was 641 grams, indicating a moisture ONAF 20c(.58) No temp SCADA 14800 liters 17kv 80 kv 4 months later content of 0.641 liters. It has been estimated that each fi lter set removes 2.6 liters of moisture at moisture levels of Table 2. 10-20 ppm. It was also found that dryer performance improved markedly with Transformer Pre dry out oil Dryer Dryer Hours of Removed Post dry out oil parameters connected removed drying moisture parameters the addition of an extra sealing washer collected in the fi lter clamping arrangement. W1 10/18MVA 23ppm 10.5.05 7.7.05 600 2.9 liters 10ppm Th e dryers were not run continuously ONAF 30c(.28Rs) 24c(.15Rs) but were switched off for periods to allow 17300 liters 36kv 80kv moisture levels to recover. A general W2 10/18MVA 25ppm 7.7.05 13.9.05 853 2.6 liters 5ppm ONAF 29c(.29Rs) 21c(.09Rs) rule of thumb for deciding when to 17300 liters 44kv 81kv cease fi ltering was when moisture levels W3 10/18 MVA 38ppm 13.9.05 14.12.05 827 3.1 liters 13ppm remained consistent at less than 20ppm, ONAF 23c(.6Rs) 31c(.15Rs) or 0.2 Aw. Th e Vaisala monitoring probes 15897 liters 37kv 83kv have proved valuable in assessing this.

Figure 6: monitoring dry out. Th is unit has the advantage of a lot the steady reduction in inlet oil moisture. Figure 6 shows data from a permanent longer fi lter life than the molecular sieve Th e fi ltering time in this example has been probe on the “L2” transformer during units. set longer than necessary (12 hrs) as outlet dry out over a 10 month period. Note Th e dryer is connected with inlet oil moisture is overshooting inlet moisture. the moisture reduction from the dryer, taken from the main tank bottom drain followed by moisture recovery as a valve and outlet oil delivered to the top oil Sustained effort required new equilibrium between the mois- drain valve. Dry outs have been carried On-line moisture monitoring can provide ture in cellulose and moisture in oil is out on three transformers so far and a a valuable condition monitoring tool for reached. Note also that as the moisture fourth one is in progress. transformers which have moisture issues, levels reduced, the degree of variation in and also for revealing transformers which moisture over each daily load cycle also Table 2: results from dryer may have moisture issues perhaps unde- reduced. which has a paper fi lter. tected by routine oil sampling. Please note: Oil parameters are from oil A common observation is that a single Paper fi lter dryer samples (i.e. KF and dielectric break- heavy overload-over temperature event Powercor has more recently purchased down tests). As these dry outs are recent, can rapidly increase moisture in oil levels another on-line dryer which has a paper follow-up oil monitoring has not yet been as moisture is driven from the cellulose fi lter. Th is unit removes moisture by carried out. Some recovery of moisture and, signifi cantly, the return of moisture pumping the oil axially through a fi lter levels is anticipated. Th is dryer also has to earlier levels may take quite a long paper roll. Moisture migrates from the oil the facility to run in “analysis” mode, period of time. to the paper as long as the paper is drier whereby the fi lter is bypassed and oil is However, monitoring alone will not than the oil. Th e unit has a quite sophis- circulated and monitored by one of the fi x anything. It is the action taken arising ticated Programmable Logic Controller moisture probes. Th is provides a moni- from monitoring which can deliver (PLC) controlled system which can re-dry toring as well as a drying capacity. condition improvement. On-line drying the paper fi lter after each fi lter cycle. Th e usually delivers a rapid improvement in unit is fi tted with moisture probes on Figure 7: typical fi ltering data. oil quality, but this improvement may not inlet and outlet oil and has a data logging Please note: left axis (Aw) scale is 0 to be permanent. Subsequent monitoring is and remote monitoring facility. 0.250; right axis (inlet oil temp) scale is 0 prudent and will often result in another Th e dryer is fi tted with a moisture to 45 deg C. Th is example shows the char- drying cycle being made. Eff ective on-line trap so actual moisture removed can be acteristic saw-tooth pattern as the fi lter drying requires a sustained eff ort which collected. fi lls with moisture and is re-dried. Note may be required for many months. n

175 / 2007 Vaisala News | 27 Timo Ranta-aho Product Line Manager and Petri Hautaniemi Project Manager Vaisala Helsinki, Finland

Small device - big performance Compact Vaisala BAROCAP® Barometer PTB110

Vaisala has introduced a new series of Standards and Technology, USA) and of barometers, the Vaisala BAROCAP® supplied with a multipoint calibration Barometer PTB110 to replace the very certificate. successful PTB100/101 series analog barometers. The new barometers are Low power consumption compact and small in every respect - Connecting/disconnecting the barom- except their overall performance. eter is easy with a removable terminal The PTB110 is a microcontroller based connector. A DIN rail mounting option barometer designed both for accurate enables the barometer to be mounted barometric pressure measurements at on a 35 mm wide standard mounting room temperature as well as for general rail. The barometer consumes very little environmental pressure monitoring over power, making it very suitable for battery a wide temperature range. The barom- or solar power operated systems where eter provides alternative pressure scales low power consumption of the system is within the range of 500...1100 hPa. The essential. The PTB110 can also be set to operating temperature ranges from -40 °C shutdown mode. Here one of the input up to +60 °C. Both voltage and frequency terminals is used as an external power outputs are available. on/power off trigger, which lowers the overall power consumption even further. Patented Vaisala technology After switching the power on, the barom- provides long-term stability eter responds very quickly. Within The Vaisala BAROCAP Barometer PTB110 The BAROCAP silicon capacitive abso- 500 ms, full accuracy pressure output is ® ® can be used in data buoys, among other lute pressure sensor, developed by Vaisala, available. applications. is the heart of the barometer. The sensor The compact PTB110 is suitable for a combines the outstanding elasticity variety of applications, such as environ- characteristics and mechanical stability mental pressure monitoring, data buoys, of single-crystal silicon with a proven laser interferometers, and in agriculture capacitive detection principle, providing and hydrology. Thanks to its very low excellent long-term stability. All PTB110 power consumption, the barometer is barometers are calibrated at the factory particularly ideal for different data logger as traceable to NIST (National Institute applications. n

28 | Vaisala News 175 / 2 0 07 Timo Ranta-aho Product Line Manager Strong under pressure and Petri Hautaniemi New barometer generation for Project Manager Vaisala atmospheric pressure measurement Helsinki, Finland

Since its introduction in 1995, the Vaisala trend and tendency code. Th e pressure used in battery powered applications. An BAROCAP® Digital Barometer PTB220 trend indicates the amount of pressure external AC supply enables the barom- has become a network and reference change, and the tendency code the eter to be connected to all universal barometer used by several meteorolog- nature of the pressure tendency during mains AC supplies. ical institutes and various customers in three hours preceding the time of obser- Th e PTB330 provides several diff erent diff erent industrial and laboratory appli- vation. Furthermore, the PTB330 can communication signals. Th e standard cations. Now we are introducing the next calculate and output the QNH and QFE output is RS232 but optionally an RS485 generation successor for this barometer: pressures used especially in aviation. Th e serial line can also be used. An optional the Vaisala BAROCAP® Digital Barometer QNH represents the pressure reduced USB connection cable enables the barom- PTB330 with several new and improved to sea level, based on the altitude and eter to be connected through its service features. temperature of the observation site, and port to a USB port of a PC. Linear voltage the QFE the air pressure at the airfi eld and current output for pressure are also Important parameter in elevation. available. many applications Th e PTB330 can be connected to a PC In meteorology, air pressure and its Added reliability through either via a terminal program or using a changes are related to low and high redundant measurement specifi c Windows® software application pressure fronts and their movements. According to the customer choice, the to transfer the measured data, which can According to the World Meteorological PTB330 can incorporate one, two or be further processed and copied to other Organization (WMO), analyzed pressure three BAROCAP® sensors. Th is unique Windows® programs. fi elds are a fundamental requirement of feature enables the customer to achieve meteorology. It is imperative that these a redundant pressure measurement. In Various installation pressure fi elds are accurately defi ned the case of two or three sensors, the possibilities as they form the basis for all subse- barometer compares the readings of the Th e housing of PTB330 is IP65 rated, quent preconditions of the state of the diff erent pressure sensors all the time enabling the unit to be installed outdoors. atmosphere. Th e atmospheric pressure and provides information on whether Th e installation can be carried out in measurements should be as accurate as these are within a set internal diff er- many diff erent ways. Th e unit can be technology allows¹. ence criteria. Th is way the user gets a mounted as such or using a separate wall Atmospheric pressure is also a crucial stable and reliable pressure reading at all mounting plate that also enables the easy parameter in aviation and important times, as well as a pre-indication of when detachment of the barometer. With the in several industrial type applications, service or recalibration is needed. mounting plate and a DIN rail kit the unit such as accurate laser interferometric can be easily connected to a standard measurements. Other measurements Display that speaks DIN rail. A pole installation kit with a rain like exhaust gas analysis in engine test your language shield is also available for mounting the benches may also require pressure As an option, the PTB330 can also incor- PTB330 onto a vertical pole. Th e Vaisala measurement. porate a graphic display, together with Static Pressure Head Series SPH10/10 is an intuitive menu-based interface. With available to minimize wind induced error As accurate as the display the outputs and units can for the measured static pressure. technology allows easily be selected by the user. Th e display Th e Vaisala BAROCAP® Digital Barom- Th e pressure measurement of the PTB330 language can be chosen from English, eter PTB330 is the latest step in the is based on the Vaisala BAROCAP® sensor German, French, Spanish, Swedish, continuous development of high accu- providing high measurement accuracy Finnish, Japanese and Russian. racy and high stability barometers. Th e and excellent long-term stability. PTB330 Th rough the graphical display the Vaisala BAROCAP® sensor represents the provides two alternative accuracy classes: user can see the trends of the selected highest barometric pressure measure- class A accuracy for the most demanding parameters in six diff erent time windows, ment quality. applications, such as using the PTB330 the longest of these being a one-year as a barometric reference, and class B history of active operation of the unit. ¹ Guide to Meteorological Instruments accuracy for more conventional use. Th e With movable cursors, the values at and Methods for Observation, WMO calibration of the PTB330 is traceable to individual time spots can be referred to - No. 8, Sixth Edition, (1996) NIST (National Institute of Standards and the minimum and maximum values and Technology, USA). observed. Th e PTB330 provides the pressure output with a pressure unit chosen by Alternative connections the customer. In addition to instant pres- Th e voltage supply ranges from 10...35 sure, it also calculates the WMO pressure VDC, allowing the PTB330 to be also

175 / 2007 Vaisala News | 29 Briefly noted 30 for measurement. sensor sensitive requiresa and low very is Marspressure on sensor to technology the Meteorological Station. Atmospheric pressure measurement instrument based on Vaisala’s reliable Martian arctic. the in phases gas and solid betweenthe cycled is water how information on the current state of the providing polar atmosphere by and role important an play will Station rological Meteo - the instruments, these With instrument. (LIDAR) ranging and detection light a as well as sensors, pressure and temperature using be will It plains. northern Martian the of weather daily the record will Agency Space Canadian the by built Station Meteorological a Mars, on operations havehospitable to microbial been life.ever ice and run tests laboratory assessing the site whether could underground to dig robotically and landing, Mars previous any than north farther site a at down touch will It months. three about for region arctic Martian the from samples ice to scheduled arrive on Marsis on May 25th 2008. planet. of on our neighboring water to seekevidence journey its began and 2007, August4th on space roaredinto mission Lander Mars Phoenix UniversityArizona-led The of Vaisala goes to Mars 13 on Finland TheChina - FinlandCleantech Conference was held inLahti, China -Finland Conference Cleantech in Lahti network. important this in Vaisala participates levels. local and regional national, on enabling cooperation between and organizationsbusinesses Finland, and China between established been have tions environment. operating Chinese the for suitable be would that and tions opera business environmental support would that model operating an create to co-operation in and actors public-sphere investors companies, engaging at aims project The working real contacts Establishing Finnishwith the Ministry of Trade andIndustry. 2006 June in launched was project The Commission. ment Environment Protection Bureau and the - Economic Develop Commission, National Development and Reform Commission, Chinese partners include the Chinese Science and Technology Finnish environmental businesses in the Chinese markets. The involving network a build to aims that project network year The Finnish EnvironmentalCluster forChina (FECC)is a two- grows stronger China – Finland cooperation |

News Vaisala The Finnish Meteorological Institute has contributed a contributed has Institute Meteorological Finnish The Throughout thecourse of thePhoenix MarsLander surface and analyzesoil collect $420 million missionwill The journey,Lander 423-million-mile the nine-month, a After - connec and networks important project, the to Thanks – 17 August 2007. The conference provided a provided conference The 2007. August 17 175 / 07 0 2 - businesses as well as the Chinese Embassy Chinese the in as Finland. well as businesses universities, from representatives including 16th, August on visitors Vantaareceived in Vaisalaheadquarters Finland. of research institutions and reference projects in different parts participants. event the of one was Vaisala ideas. exchange and meet to tions organiza - research and companies environmental for venue Hannu Talvitie introducing Vaisala visitors. productstotheChinese walls of theVictoria of walls Crater on NASA/JPL-Cornell. Mars. Courtesy St. Vincent, one promontories themany of Cape out that jut from the h Ciee uss lo iie Fnih companies, Finnish visited also guests Chinese The now get almost round-the-clock service without having to having without service round-the-clock almost get now can you coverage, global our to Thanks world. the over all staff sales knowledgeable our by operated is chat live The website. our through experts VaisalaInstruments with chat live in engage to able been have you 2006 December Since Chat live with Vaisala experts Instruments toto Vaisala send them to answer. Experts theory. If you do not find an answer toyour questions, feel free have also included sections for calibration Weand measurement them. use to how on information and products our on Industrial in the Knowledge Center Instruments section. made new a have launched have we and highlight, additional an As pages. regularly, product and application websites our to updates smaller numerous existing our updating are We Centerfor instruments industrial Knowledge sites concentrate Industrial on the Instruments offering. coming next with a focus on Latin-American customers. Both our especially Brazilianserves customers. The Spanish is site and summer the during launched was site Portuguese The languages. new two in appear will pages web localized its that reported division Instruments Vaisala the year Last websites New localized our customers. to better serve sections, Industrial Instruments and Weather Measurement,main two into divided was site the facelift, the with Along layout in May. page front new The a website got Vaisala.com Vaisala.com updates New in Vaisala websites The KnowledgeCenter servesas an easy channel for details Contact the Vaisala the Contact News team http://www.vaisala.com/Instruments/KnowledgeCenter http://www.vaisala.com/Instruments/KnowledgeCenter http://www.vaisala.com/br http://www.vaisala.com/br metric pressure,metric carbon dioxide, oxygen andwind. baro - oil, in moisturehumidity, measuring dewpoint, ments instru- included have we Currently side-by-side. products compare and then the productneeds offering your match to our narrow to easy is it Vaisala.com on Advisor Product or comparing the specifications? With the recently launched Are troublehaving a finding suitable you instrument Vaisala Advisor tool Product Instruments chatting andstart pages, with Vaisala experts. possible. as soon as representative local your by contacted be and message a leave can you online, operators no are there If overseas. call to stay version. latest with the up to date feature in the near future. Visit calculation the Humidity bulb Calculator wet pages much-requested the in bring to plan pastyear. the during we as majorupdate a for time Now itis times several updated was Calculator Humidity The Vaisala Vaisala Calculator 2.0 Humidity Locate “Maria” on the right-hand side of the Industrial the of side right-hand the on “Maria” Locate Thank you intrest. for Thank your [email protected] to email an by sending please Vaisalateam the contact News offeedback changes and address, For cancellations, subscriptions, http://www.vaisala.com/HumidityCalculator http://www.vaisala.com/HumidityCalculator Marikka Nevamäki 175 http://www.vaisala.com/Advisor http://www.vaisala.com/Advisor Editor-in-Chief / 2007 News Vaisala |

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C210047EN 2007-10