Gas Standards for Natural Gas Odorant Analysis
NPL provides primary reference natural gas mixtures (PRGMs) for sale. Each standard can contain single or multi-component species and is carefully prepared to meet specific customer requirements.
Sulphur-containing species are added to natural gas to provide a distinctive odour, thus allowing any potentially hazardous leaks to be detected. The very low odour thresholds of these compounds enable detection by the human nose at minute concentrations.
NPL also supplies natural gas standards for composition analysis. A flyer detailing NPL's range of natural gas and sulphur odorant standards is available for download (
PDF 4.18 MB).
Scope of UKAS Accreditation
The preparation and analysis of these standards forms part of NPL's UKAS Reference Materials (Guide 34) and Calibration (ISO 17025) scopes of accreditation. Each standard is prepared gravimetrically (in accordance with ISO 6142) and analysed against internationally recognised standards by NPL's own QA laboratory. NPL's odorant standards are available in a matrix of methane or nitrogen. A full list of accredited components is given in the table below:
| Component | Structure | Amount Fraction Range (μmol/mol) |
Best Measurement Capability* (μmol/mol) |
|
| Hydrogen sulphide |
H2S |
0.4 - 5000 |
For all components
|
|
| Carbonyl sulphide |
OCS |
0.4 - 5000 | ||
| Carbon disulphide |
CS2 |
0.4 - 200 | ||
| Dimethyl sulphide |
CH3-S-CH3 |
0.4 - 200 | ||
| Ethyl methyl sulphide |
CH3-CH2-S-CH3 |
0.4 - 200 | ||
| Diethyl sulphide |
CH3-CH2-S-CH2-CH3 |
0.4 - 200 | ||
| Methyl mercaptan (Methanethiol) |
CH3-SH |
0.4 - 200 | ||
| Ethyl mercaptan (Ethanethiol) |
CH3-CH2-SH |
0.4 - 200 | ||
| i-propyl mercaptan (2-propanethiol) |
SH |
0.4 - 200 | ||
| n-propyl mercaptan (1-propanethiol) |
CH3-CH2-CH2-SH |
0.4 - 200 | ||
| tert-butyl mercaptan (2-methyl-2-propanethiol) |
CH3 |
0.4 - 200 | ||
| THT (tetrahydrothiophene) |
|
0.4 - 200 |
Non-sulphur odorant standards
NPL also supplies a range of non-sulphur odorant PRGMs in order to provide traceability for the measurement of non-sulphur odorant species, which are increasingly being used in natural gas across Europe. Standards are available containing the following components, which are present in the most common non-sulphur odorant mixture, Gasodor® S-Free:
- Methylacrylate
- Ethylacrylate
- Methylethylpyrazine
Other components are available on request.
Related standards and services
In addition to its range of natural gas standards, NPL also:
- Provides a UKAS accredited range of natural gas standards
- Provides a range of refinery gas standards
- Organises proficiency testing (PT) schemes to enable laboratories to achieve
greater confidence in their analyses of natural gas and refinery gas composition - Provides a range of LPG, LNG and other liquid hydrocarbon standard mixtures
Contact
Customer Service tel: +44 20 8943 8637
E-mail: gases_enquiries@npl.co.uk