Particle Size Calibration Methods and Standards for Particle Counters

摘要

In particle counters, there are light scattering method and light extinction (blocking; obscuration) method for detection of liquid-borne particles. Light scattering method is also used for measuring airborne particles. Particle counters are used in electronic, pharmaceutical, hydraulic fluid power and other industries. Each industry has their own standards for calibration of particle counters. JIS B 9932 and ISO 11171 require polydisperse particles for calibration, meanwhile JIS B 9921, JIS B 9925, JP and USP require monodisperse particles for calibration. There are several kinds of method for calibrations and evaluations of particle counters. This article describes the differences in particle-detector structure of particle counters, and the differences in calibration method of particle counters in existent standards.