BS EN 14626:2024

Ambient air. Standard method for the measurement of the concentration of carbon monoxide by non-dispersive infrared spectroscopy. | Status: Current

1 Scope This document specifies a continuous measurement method for the determination of the concentration of carbon monoxide present in ambient air based on the non-dispersive infrared spectroscopic measuring principle. This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate non-dispersive infrared spectroscopic analyser by means of type testing. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site in order to meet data quality requirements (see Annex I of Directive 2008/50/EC[1] for additional information) and requirements during sampling, calibration and quality assurance for use. The method is applicable to the determination of the mass concentration of carbon monoxide present in ambient air up to 100 mg/m3 of carbon monoxide. This concentration range represents the certification range for type testing.

NOTE 1 Other ranges can be used depending on the levels present in ambient air.

NOTE 2 When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements might not apply.

The method covers the determination of ambient air concentrations of carbon monoxide in locations classified as rural areas, urban-background areas, and for sampling points influenced by traffic or industrial sources. The results are expressed in mg/m3 (at 20 °C and 101,3 kPa).

NOTE 3 100 mg/m3 of CO corresponds to 86 µmol/mol of CO.

This document contains information for different groups of users. Clause 5 to Clause 7 and Annex B, Annex C and Annex D contain general information about the principles of carbon monoxide measurement by non-dispersive infrared spectroscopic analyser and sampling equipment. Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type testing of carbon monoxide analysers. These sections contain information about:

• — type testing conditions, test procedures and test requirements;
• — analyser performance requirements;
• — evaluation of the type testing results;
• — evaluation of the associated uncertainty of the measurement performed by the carbon monoxide analyser based on the type testing results.

Clause 9 to Clause 11 and Annex F are directed towards monitoring networks performing the practical measurements of carbon monoxide in ambient air. These sections contain information about:

• — initial installation of the analyser in the monitoring network and acceptance testing;
• — ongoing quality assurance/quality control;
• — calculation and reporting of measurement results;
• — evaluation of the uncertainty to the measurement results under practical monitoring conditions.

This document represents an evolution of earlier editions (EN 14626:2005 and EN 14626:2012).

NOTE 4 Analysers type tested prior to the publication of this document can still be used for regulated monitoring purposes. As newer versions of analysers tested under this document become available, discontinue the use of older reference analysers.