UNE-EN 12341:2024

This document describes a standard method for determining the PM10 or PM2,5 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 m3/h, over a nominal sampling period of 24 h. Measurement results are expressed in ¼g/m3, 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 ¼g/m3 (i.e. the limit of detection of the standard measurement method expressed as its uncertainty) up to 150 ¼g/m3 for PM10 and 120 ¼g/m3 for PM2,5.

NOTE 1 Although the European Standard is not validated for higher concentrations, its range of application could well be extended to ambient air concentrations up to circa 200 ¼g/m3 when using suitable filter materials (see 5.1.5.2).

This document 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 the European Union for the measurement of concentrations in ambient air of PM10 or PM2,5. However, this document does not exclude the use of single-filter samplers.

NOTE 2 Older versions of samplers, which conform to previous versions of EN 12341, can still be used to evaluate equivalence of candidate methods, using the procedures described in EN 16450 and in [11]. As newer versions of samplers tested under this document become available, discontinue the use of older reference samplers in EN 16450 and in [11]. Type testing reports of equivalent methods are still valid if they were commissioned prior to the availability of reference methods tested under this document.

This document also provides guidance for the selection and testing of filters with the aim of reducing the measurement uncertainty of the results obtained when applying this document.