What is meant by an iso-kinetic calibration system traceable to national standards?
This refers to the way in which the Microdust pro is calibrated. After manufacturing, there is a special calibration process using a wind tunnel. Fine reference dust is injected into the tunnel using a Wright Dust Feeder, which is pulled through the tunnel and through the Microdust probe (figure 5). After the airstream has passed through the probe, it is collected on a filter to establish a known and correct gravimetric result. The term “iso-kinetic” refers to the matching of air velocities through the sampling volume. The instrumentation used for this is calibrated as part of the ISO9001 accreditation. The filter is weighed before and after the process and the difference is the collected mass of particulate. This value is then compared to the real time data collected by the Microdust pro instrument (specifically the average over the sampling period) and the instrument is adjusted so that the two values are the same. This implies that the unit is now calibrated to a known reference val
