National Physical Laboratory

Purity analysis

Purity analysis

A wide range of regulations and industrial requirements depend on the accurate and robust analysis of trace and ultra-trace concentrations of components in 'pure' gases. Examples of the areas where these analyses are highly important are atmospheric monitoring, ambient air and indoor air quality. They are also essential for process gases used in, for example, the health, micro-manufacturing, fuel cell and energy industries.

The NPL trace gas analysis facility provides traceable measurements of key contaminants found in high-purity gases. Measurement traceability is achieved through instrument calibrations using in-house traceable gas standards. NPL's purity analysis capability is summarised in the table below:

Component Approximate limit of detection (nmol/mol)
Nitrogen 10
Oxygen 10
Argon 10
Hydrogen 10
Carbon monoxide 1
Carbon dioxide 5
Sulphur dioxide 1
Component Approximate limit of detection (nmol/mol)
Nitrogen monoxide 1
Nitrogen dioxide 1
Methane 3
Other hydrocarbons 1
Water 2
Hydrogen sulphide 5

The NPL trace gas analysis facility is also available for instrument calibration and performance assessment work.


Please email or telephone Customer Services on +44 20 8943 6151.

Last Updated: 16 Jun 2016
Created: 24 Sep 2013


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