Traceable in-house preparation of RM CO2/N2 gas mixture using gravimetric standardized method |
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| Najji H. AlYami, Abdullah S. AlOwaysi, Khaled M. Ahmed |
- Abstract:
- The necessity for national and international programs to monitor the levels of carbon dioxide emissions in the atmosphere has arisen as a result of the recent large greenhouse gas emissions that cause a rise in the Earth's temperature and climate changes with severe impacts. In order to give confidence in the monitoring results and enable the proper decisions to be made regarding the supply of environmental treatment and air quality through the limiting and monitoring of emission, it is required to maintain the traceability of the measurement data to SI units. Gas measurements laboratory at SASO-NMCC uses the gravimetric method to prepare reference gas mixtures of CO2 in N2 as primary standard mixtures (PSMs) cylinders based on universal gas law. The produced PSMs used as working standards to transfer the traceability from CRMs to customers’ artefacts. The used method fully complies with ISO 6142. Description of the steps of the production process and its method verification as well as equipment used and associated uncertainty are presented in this work. In accordance with the requirements of ISO 6143, a validated gas chromatography thermal conductivity detector (GC-TCD) method was selected to verify the mole fraction of the gravimetrically prepared gas mixtures. Reproducibility of the produced concentrations is demonstrated through mid-term and long-term evaluations. Eight certified reference materials (CRMs) of different concentrations were used for the GC calibration to provide metrological traceability of the measurement results to SI units. Associated uncertainty budget, with brief description of different components and error sources, is presented
- Keywords:
- Reference Materials (RMs), Primary Standard Mixtures (PSMs), CRMs, CO2, GC-TCD, ISO 6142 & 6143.
- Download:
- IMEKO-TC24-2023-06.pdf
- DOI:
- 10.21014/tc24-2023.06
- Event details
- IMEKO TC:
- TC24
- Event name:
- IMEKO TC8, TC11 and TC24 Conference
- Title:
New Perspectives in Chemical Measurements
- Place:
- Madeira, PORTUGAL
- Time:
- 11 October 2023 - 13 October 2023