Ambient air - Measurement of the mass of the particulate matter on a filter medium - Beta-ray absorption method
This International Standard describes a method for the measurement of the mass of particulate matter in ambient air and is based on the absorption of beta rays by the particulate matter.
This method applies to the determination of concentrations ranging from a few micrograms per cubic metre to a few milligrams per cubic metre contained in the atmospheres of urban, rural or industrial areas.
The lower mass detection limit of the method is usually 15 µg to 30 µg of deposited mass per square centimetre of surface area, S, of the filter. This means, for a sampling time t of 3 h and a flowrate q of 1 m 3 /h,that the concentration detection limit ranges between 5 µg/m 3 and 10 µg/m 3 , computed as follows: