Historical
ISO 21501-4:2007
Determination of particle size distribution - Single particle light interaction methods - Part 4: Light scattering airborne particle counter for clean spaces
ISO 21501-4:2007 describes a calibration and verification method for a light scattering airborne particle counter (LSAPC), which is used to measure the size and particle number concentration of particles suspended in air. The light scattering method described in ISO 21501-4:2007 is based on single particle measurements. The typical size range of particles measured by this method is between 0,1 ╡m and 10 ╡m in particle size.
Instruments that conform to ISO 21501-4:2007 are used for the classification of air cleanliness in cleanrooms and associated controlled environments in accordance with ISO 14644-1, as well as the measurement of number and size distribution of particles in various environments.
The following are within the scope of ISO 21501-4:2007:
- size calibration;
- verification of size setting;
- counting efficiency;
- size resolution;
- false count rate;
- maximum particle number concentration;
- sampling flow rate;
- sampling time;
- sampling volume;
- calibration interval;
- test report.
International Organization for Standardization [iso]
