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Gas reference materials

Air quality monitoring

Monitoring and improving air quality

Routine measurements of air pollutants such as sulphur dioxide, oxides of nitrogen, carbon monoxide and benzene must be performed to fulfil the requirements of the EC Directive on ambient air quality and cleaner air for Europe (Directive 2008/50/EC).

NPL's provides gas standards for calibrating air quality monitors. Mixtures that meet the uncertainty requirements of Directive 2008/50/EC are shown below. Other mixtures may be available on request.

Component Matrix gas Amount fraction range
From To
Sulphur dioxide Nitrogen or air 100 nmol/mol 10 mmol/mol
Nitrogen monoxide Nitrogen 100 nmol/mol 10 mmol/mol
Nitrogen dioxide Nitrogen or air 1 µmol/mol 5 mmol/mol
Carbon monoxide Nitrogen or air 1 μmol/mol 500 μmol/mol

Standards of benzene and other hydrocarbon compounds are also available.

Don’t see what you are looking for? Our diverse skill set enables us to provide bespoke solutions. Please contact us to discuss your requirements.

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