# The Air Quality Standards (Wales) Regulations 2007, Paragraph 5: Reference methods


The reference method for the analysis of oxides of nitrogen is ISO 7996:1985, Ambient air — determination of the mass concentrations of nitrogen oxides — chemiluminescence method.

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Source: https://www.legislation.gov.uk/wsi/2007/717/schedule/10/paragraph/5 (the official version)
Page: https://openlegislation.uk/air-quality-standards-wales-regulations-2007/schedule-10/paragraph-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.