Comparison of analytical capabilities for nitrogen monoxide in nitrogen at ambient levels (450 nmol/mol)

Project Description

Standard gas mixtures of nitrogen monoxide in nitrogen are used to disseminate traceability to stations monitoring ambient air quality throughout the EU. These measurements fulfil the requirements of the EU Air Quality Directive.

A key comparison (CCQM-K26a) of standard gas mixtures of nitrogen monoxide in nitrogen was coordinated by NPL for the CCQM in 2004/5. Seven of the 12 participating NMIs were within EURAMET. It involved the preparation and labelling of a batch of standard mixtures at 720 nmol/mol and dissemination of them to the participating NMIs for analysis.

It is generally considered that the state of the art for measurements of nitrogen monoxide in nitrogen has improved significantly since CCQM-K26a was completed. It is therefore proposed to organise another key comparison. This will test the capabilities of NMIs to analyse an unknown mixture at a nominal amount fraction of 450 nmol/mol. At present, 5 NMIs (NPL, VSL, LNE, UBA(D) and FMI) in EURAMET have CMCs for this analysis. In addition, several other NMIs have CMCs for the analysis of nitrogen monoxide at higher amount fractions.

Participants will be required to analyze a nitrogen monoxide in nitrogen mixture at an amount fraction close to 450 nmol/mol. Participants will pay the cost of returning the mixture to the coordinating laboratory (NPL):

Timing: - It is planned that the cylinders will be despatched to participants in January 2012.

 Final Report 2018-04-18

The comparison has been completed and results are published in the KCDB.