This Technical Specification supplements the requirements of EN ISO/IEC 17025:2005, and is suitable for the demonstration of competence of laboratories that undertake periodic measurement of emissions from stationary sources including the taking of representative samples of emissions and subsequent laboratory analysis for gases and for particulate species, the determination of reference quantities such as temperature, pressure, water vapour and oxygen content in the field and the use of portable instruments (such as hand held instruments and transportable instruments used in mobile laboratories) in the field.This Technical Specification is applicable to all laboratories undertaking the periodic measurement of emissions from stationary sources, the calibration of installed automated measuring systems in accordance with EN 14181:2004 and/or the field testing of automated measuring systems for conformity assessment purposes.