ISO 29463-2-2011 pdf free download.High-efficiency filters and filter media for removing particles in air — Part 2: Aerosol production, measuring equipment and particle-counting statistics.
5.3.5 Calibration
It is possible to calculate the diameter of the mono-disperse output aerosol from the known geometry of the apparatus, the volume flow rate and the applied potential difference. For this reason, the apparatus is often used as a calibration standard. The proper function of the apparatus should be checked at regular time intervals by using reference filters with known efficiency at specific particle sizes. If it seems that the apparatus is not working properly, a comparison with another device of the same type, or the use of PSL aerosols (see also References [8] and [15]) can be necessary to calibrate the apparatus. 5.4 Particle size analysis system on the basis of differential mobility analysis
5.4.1 Operation
The differential mobility particle sizer (DMPS) described in this subclause involves a combination of a DMA and a CPC. If the number concentration of the mono-disperse aerosol is measured at the output of the DMA with a number of suitable central electrode voltages, then the size distribution of the initial poly-disperse aerosol can be calculated if the distribution of the electrical charges on the aerosol particles is known. The measurement process of the DMPS is controlled by the same computer that evaluates the measurement data.
5.4.2 Minimum performance parameters
The following apply:
a) sampling volume flow rate: 0,3 l/min;
b) measuring range:
1) for the particle size: 10 nm to 0,8 µm,
2) for the particle concentration: 10 3 cm 3 to 10 6 cm 3 .
5.4.3 Sources of errors and error limits
In order to use this measuring method, it is necessary to know the charge distribution for the aerosol. The charging mechanism of the particles can be disturbed by the composition of the carrier gas (e.g. alcohol molecules), but also by concentrations of particles that are too high.
5.4.4 Maintenance and inspection
See 5.2.4 (CPC) and 5.3.4 (DMA).
5.4.5 Calibration
See 5.2.5 (CPC) and 5.3.5 (DMA).ISO 29463-2 pdf download.