Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/1076124
32 | January 2019 In upcoming installments of this series, I'll attempt to outline how ISO 21501-4 resolved the manufacturing is- sues, what some of the challenges are in using PM2.5 as an air quality standard and outline some thoughts on what a commercial air quality instrumentation and industry stan- dards might look like. It's interesting to note that this standard initially made it impossible for any of the current manufacturers to ship a product that met the standard. Every one of them had to go through a significant redesign process in order to meet this new standard. It's certain that some of the smaller man- ufacturers could not meet this standard and that over the years many potential manufacturers have been unable to clear this hurdle and bring credible products into the space. But, what this did was make it possible for instruments that met the standard to agree with a much higher degree of correlation on the particle counts by size within an environ- ment. This made it possible for the cleanroom industry to rely on these instruments to control their processes. As an example, the figure below shows two instruments from our production line connected together by a tube with a Y in it to ensure they are sampling from the same air and run with 1 minute samples over a 12 hour period. We can see by the plots (each one showing a different size channel 0.3um through 10um). As we can see the instruments have a very high degree of correlation to each other in all channels. Because of ISO 21501-4 all our instruments track sim- ilarly. And, with a high-quality calibration system we find that we instruments calibrated many months apart also track with similar correlation. So, what does this mean for the commercial air quality space? It's important to note that what drove this growth and the development of these instruments in the clean- room space was the enormous demand for these prod- ucts. Because of that demand the industry grew quickly with whatever instruments were at hand being consumed by clients initially without much oversight or discrimina- tion. We believe that we're seeing similar conditions to- day in the commercial air quality space. There is an enor- mous appetite for instrumentation and sensors to monitor air quality in many environments and applications. And, many of the vendors in the space are making unsupported or misinformed claims and selling entirely unsuitable prod- ucts to unsuspecting clients who have no simple means to determine suitability. We believe that clients will soon demand that these in- struments meet some air quality instrument manufacturing standard (yet to be defined). And, that doing so will cer- tainly change the playing field and move us toward the day where a client can choose between various instruments based on features, price, service, etc. and be able to rely that adherence of that instrument to a manufacturing stan- dard will ensure that they can rely on that instrument to provide them with accurate information. About the Author David Pariseau is an embedded systems design en- gineer with 36 years of development experience in con- sumer electronics, financial payment, medical devices, lab instrumen tation, industrial controls, and machine design. David was the original founder of Lighthouse Associates (now known as Lighthouse Worldwide Solutions) in 1985, Technology Plus in 1995 and SinoEV Technologies in 2009. He co-founded Particles Plus in 2010 which is focused on bringing quality products into the mainstream commercial air quality monitoring space. He can be reached at dpariseau@particlesplus.com