By Isidro Sanchez, Applications Engineer, Particle Measuring Systems
Establishing and maintaining cleanroom performance of aerosol particles in a cleanroom often requires the use of multiple particle counters with varying design parameters and display settings. Commonly, cleanroom personnel employ the use of multiple optical particle counters (as defined in ISO 14644-1) to report an array of airborne particle counts. This paper is a summary of the basic methods cleanroom personnel may use to ensure that the data that is reported by different aerosol particle counters can be compared effectively. This is accomplished by making sure differences are understood and appropriate data conversions can be made to make meaningful comparisons. OPCs for Statistical Process Control (SPC) is outlined along with how SPC statistical rules are applied when using metrology instruments to establish and maintain process control in airborne particle counts of a cleanroom, even with the use of different instruments.