UNI EN 12341:2023

This document specifies a standard method for determining the PM10 or PM 2,5 mass concentrations of suspended particulate matter in ambient air by sampling the particulate matter on filters and weighing them by means of a balance. Measurements are performed with samplers with inlet designs as specified in Annex A, operating at a nominal flow rate of 2,3 m 3/h, over a nominal sampling period of 24 h. The method covers the determination of ambient air concentrations of specific fractions of suspended particulate matter in zones classified as rural areas, urban-background areas, traffic-orientated locations and locations influenced by industrial sources. Measurement results are expressed in μg/m 3, where the volume of air is the volume at ambient conditions near the inlet at the time of sampling. The range of application of this document is for 24 h measurements from approximately 1 μg/m 3 (i.e. the limit of detection of the standard measurement method expressed as its uncertainty) up to 150 μg/m 3 for PM 10 and 120 μg/m 3 for PM 2,5.