BS EN 12341:2023

This European Standard describes a standard method for determining the PM10 or PM2,5 mass concentrations of suspendedparticulate 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 m3/h,over a nominal sampling period of 24 h. Measurement results are expressed in μg/m3, where the volume of air is the volume atambient conditions near the inlet at the time of sampling. The range of application of this European Standard is for 24 h measurements from approximately 1 μg/m3 (i.e. the limit of detection ofthe standard measurement method expressed as its uncertainty) up to 150 μg/m3 for PM10 and 120 μg/m3 for PM2,5. This European Standard describes procedures and gives requirements for the testing and use of so-called sequential samplers,equipped with a filter changer, suitable for extended stand-alone operation. Sequential samplers are commonly used throughout theEuropean Union for the measurement of concentrations in ambient air of PM10 or PM2,5. However, this European Standard does notexclude the use of single-filter samplers. This European Standard represents an evolution of earlier European Standards (EN 12341:1998 and 2014, EN 14907:2005). Newequipment procured shall comply fully with this European Standard. Older versions of these samplers, including those described in EN 12341:2014 Annex B, have a special status in terms of their use. These samplers can still be used for monitoring purposes and for ongoing quality control, provided that a well justified additionalallowance is made to their uncertainties This European Standard also provides guidance for the selection and testing of filters with the aim of reducing the measurementuncertainty of the results obtained when applying this European Standard.