Bilateral comparison of vehicle emission standards

Project Description

The rationale for the comparison is the evaluation of the preparative capability of CEM. The other objective is to compare under repeatability conditions the capability measurement.

Two gas mixtures will be prepared by means of primary methods (gravimetry) at the pilot laboratory (CEM) ISO 6142 (Preparation of calibration gas mixtures. Gravimetric method). These gas mixtures will be analysed by CEM to check their composition before sending the cylinders to the NPL. Analysis will be made in accordance with ISO 6143 (Gas Analysis – Comparison methods for determining and checking the composition of calibration gas mixtures).

The nominal compositions of the mixtures will be:

• Mixture 1 - C₃H₈ =1 mmol/mol; CO₂ = 50 mmol/mol; CO = 75 mmol/mol; N₂ balance
• Mixture 2 - O₂ = 1.5 mmol/mol;> N₂ balance

Final Report 2005-03-31

The comparison has been completed and the report can be downloaded here>>.