Palas®Particular Nr. 2 | 2007 Information for customers and partners of Palas® GmbH New test rig guarantees Dear Readers, highest quality By the close exchange with Exclusive service for the calibration of aerosol generators our partners and customers we are acquainted with the chal- lenges arising in practice. Again Since middle of 2007, the Pa- upon the manufac- and again it can be seen that on- las® measuring laboratory has turer, only within the ly with individual solutions we been working at full capacity. concentration range achieve together our aim. The This is due to a new test rig offe- between 103 - 2x105 “improvised” soot generation de- ring an unrivalled wide spectrum particles/cm3. There- scribed in this edition is such a for calibrations. For approximate- fore, the test aerosol case. The highly-special require- ly four months the faultless quali- must be made mea- ments of our customers are the ty of each Palas® aerosol genera- surable first. That reason why our service is not li- tor has been backed up with this happens in the new mited to the established Palas® fluidic-optimised and stably wor- calibration test rig. In product range. Our task compri- king test rig. contrast, so called ses also the realisation of tech- With the new calibration test rig, clean room counters nical special solutions together the device parameters of aerosol are not suitable for with our customers. Often, new generators regarding particle size the calibration of products have their seeds in this and particle concentration can be such test aerosols. continuous development work. clearly determined. This applies to „For calibration, Practice proximity is very impor- most different dusts, salt particles the aerosol genera- tant also with the development of and droplets as well as to the di- tor is attached to the technical standards. Especially verse operating conditions and aerosol processing on international level it is impor- setting parameters of the different tube“, describes Möl- tant to consider the experience of aerosol generators. ter the procedure. Measurable quality: The new Palas® test rig German companies as well. The- „This test rig was originally con- There is a tube for refore, Palas® employees colla- ceived only for internal quality dust particles, a tube borate in different DIN, ISO and control“ says Palas® Managing for liquid droplets such as DEHS with the aerosol spectrometer VDI committees. Director Leander Mölter. Now, the and a tube for salt particles. In the welas® according to the guide- new calibration test rig serves no aerosol processing tube, the aero- lines VDI 3867 and/or ISO/DIS Leander Mölter longer only for the outgoing in- sol is distributed homogeneously 21501-1. The size classification Managing Director spection of the Palas® aerosol ge- over the cross section. The sam- accuracy and the size resolution Palas® GmbH nerators. Palas® offers also its cu- pling takes place in an isokinetic are proven reliably over the mea- stomers and its partners an unusual way, i.e. at constant speed and in suring range. In addition, the service with this test rig. The main- vertical arrangement. Thus it is en- welas® system has a coincidence In this edition: tenance of the aerosol generator sured that one gets also large par- detection. Cover topic: New test rig is done with this test rig – in case ticles of for example 40 µm repre- Not only generators made by guarantees highest quality of ambiguities a broad and fast di- sentatively into the measuring Palas® are calibrated Practice: Practical filter testing agnostics can be placed. device. Technically unusual: the in- with open flame flow can be alternatively adjusted Not only generators made by The test aerosols must be Customers: Hollingsworth & to pressure, suction, circulating air Palas® are calibrated. Also com- made measurable Vose or mixture operation. The volume mercial aerosol generators made Development: welas® system „The quality of the measurement flow can be variably set stably by other manufacturers can be covers wide measuring results obtained with test aerosols between 40 and 600 m3/h with sounded out with this test rig. Möl- spectrum depends on the reliable calibrati- an accuracy of one per cent of the ter assures: „Everyone having its Development: Palas® on of the used generators“, ex- final value. generator tested with us gets from collaboration in standards plains Mölter. Commercial aero- The measurement of the particle us naturally a Palas® calibration committees sol spectrometers can measure concentration and of the particle certificate including the current va- Internal: Retrospect 21st ATS coincidence-freely, depending size distribution is accomplished lues of the calibrated device.“ Palas®Particular 2 | 2007 Palas® Practice Practical filter testing with open flame Improvised soot generator shows filter performance of nanofibres The automotive industry continu- no test equipment was available” ously requires new and innovative describes Mr. Schnieders the star- concepts to increase the perfor- ting position. ”The soot emission mance of filter media. The efficient from the Palas® VSG-3000 simply capturing of fine particular matter is too high. The particle concentra- – above all soot – currently is the tion of the VSG-3010C, designed main scope of these discussions. for calibration of the big genera- The Hollingsworth & Vose Com- tor, on the other hand is too low to pany (USA) develops filter me- get useful results in an acceptable dia which are coated with nano- time.“ fibres. The use of such nanofibre Test results using a “camping coated filter media in field tests ha- stove” ve shown great improvement with much higher efficiencies compa- Based on the Palas® principle of red to conventional cellulose pa- generating soot using a combusti- pers for the finest particles. Beside on process an improvised solution „Real Diesel soot “ on filter test system this, the life of the filter media is ex- has been found, giving amazing tended as well. results. A simple paraffin flame ted with the AGK-2000 aerosol thing‘ particles from brakes, unceremoniously has been used generator from Palas®, have wheels and road dust – all these How to show the filter as soot generator, “supplying an shown the same advantages and will be part of the overall particle performance of nanofibres? unexpectedly constant soot gene- improvements of the nanofibres as mixture. Therefore the next task is It is difficult to show the benefits ration source”, according to Mr. they have shown with soot - even if to approach the real life condi- of nanofibres in filtration if the me- Schnieders. This ‚generator‘ has the particle characteristics of tions much better.” In cooperation dia is tested in the laboratory, re- been combined with the Palas® NaCl and soot are quite different. with the Palas® company the possi- ports Immo Schnieders from Hol- MMTC- 2000 test equipment for bility of a soot generator is evalua- What is the particle distributi- lingsworth & Vose Company. ”The cleanable filter media to test the ted as well as the possibility to si- on in the `real world`? standardized tests using AC Fine nanofibre media with soot. With mulate soot-conditions with aerosol test dust do not reflect the merits of success: „The reproducibility of According to Mr. Schnieders, generators, which are able to ad- the nanofibre coated media. Of the results certainly is only partial- there are still more open questions: just the appropriate particle sizes course there is recognizable im- ly verified“, explains Mr. Schnie- “What is the particle distribution quite easily using different particle provement of the efficiency, but ders, „but with the improvised in the `real world`? If one is only size distributions of the NaCl solu- the advantages of such media in a equipment we are able to show measuring with soot it is not consi- tions. fine particular environment are not the strong differences for nano- dered that trucks are also ‚brea- shown. This makes the commer- fibre coated media if they are cialization of such media more dif- measured with ´real´ soot and ® ficult”. Furthermore the tests have we can demonstrate the huge be- Palas Customers not shown the increased life of the nefit of nanofibres in the capture nanofibre media due to the fact of finest soot particles“. that existing test standards are not Of course this is not a really ri- comparable to real life conditions. gorous scientific work, confesses “The particle size distribution of Schnieders, but the results are an Hollingsworth & Vose is one The expertise and process capa- the standard AC Fine test dust with important basis to adapt the exi- of the worldwide leading manu- bilities include wet laid, dry laid, the presence of extremely large sting test protocols towards more facturers of special papers and melt blown, and composite tech- particles is not comparable to soot realistic conditions and to develop nonwovens for technical appli- nologies. - which is a heightened area of filter media for fine particle emissi- cations. With its advanced R&D Hollingsworth & Vose is opera- concern in the debate of fine par- ons. and pilot manufacturing facilities, ting twelve manufacturing sites ticular matter”, says Mr. Schnie- Together with Martin Schmidt Hollingsworth & Vose drives va- in Europe, North America and ders. As consequence the test pro- from Palas® alternatives are now lue in their customers‘ products Asia. Since 2007 a new ma- tocol has to be adapted towards being evaluated. The adjustment by inventing next-generation