For air quality across the European Union to be assessed on a consistent basis, Member States shall employ standard measurement techniques and procedures. The aim of DIN EN 12341 is to present a harmonized methodology for monitoring the mass concentrations of suspended particulate matter (PM10 and PM2,5, respectively) in ambient air, following Directive 2008/50/EC on ambient air quality and cleaner air for Europe which sets the parameters specific to the assessment of ambient concentration levels of particulate matter. DIN EN 12341 merges the earlier European Standards DIN EN 12341:1998 and DIN EN 14907:2005 with the aim of harmonizing the very similar procedures that are used to measure mass concentrations of both fractions of particulate matter in ambient air. DIN EN 12341 contains - a description of a manual gravimetric standard measurement method for PM10 or PM2,5 using sequential samplers or single-filter samplers; - a summary of performance requirements of the method; - requirements for suitability testing of facilities and equipment on initial application of the method; - requirements for ongoing quality assurance/quality control when applying the method in the field; - the assessment of measurement uncertainty of the results; - criteria and test methods for the evaluation of the suitability of filters for application using this method. The methods illustrated in DIN EN 12341 are in particular directed at representatives of authorities, monitoring network operators, measuring institutes, test laboratories and measuring instrument manufacturers. The standard has been prepared by CEN/TC 264 "Air quality", the secretariat of which is held by DIN, in Working Group CEN/TC 264/WG 15 "Particulate Matter PM10/PM2,5". The responsible German committee is NA 134-04-02-09 UA "Messen von Partikeln in der Außenluft" ("Measurement of particles in ambient air").