Air Quality Instrumentation Part II: A Manufacturing Standard
In the previous installment I provided a brief history of air quality in the cleanroom space. Essentially briefly chronicling the rapid rise of instrumentation followed by a need for standards to control the manufacturing of these instruments so they could better suit the industry they were serving. In this installment we’ll look a bit more closely at the ISO standard (specifically ISO 21501-4) that emerged. We’ll go through each of the requirements and discuss why this was included and what it sought to control. Ultimately, we’re attempting to lay the groundwork for a similar effort vis-a-vis air quality sensors in the air quality space. The hope is that understanding developments in industrial air quality monitoring will serve as a useful starting point.
ISO 21501-4 (or part 4) applies specifically to “Light scattering airborne particle counters for clean spaces”. There are certainly other ways to measure air quality, and in indoor and outdoor air quality most of the sensors are not particle counters, but it’s still instructive to use this standard point in discussing what an air quality instrument standard should address.