New Primary Low-Pressure Gas Flow Standard at NIMT |
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| Sutham Masri, Win-Ti Lin , Chun-Min Su |
- Abstract:
- To establish the traceability chain of low-pressure gas flow measurement within Thailand, a primary standard with the capacity of 0.005 L/min to 24 L/min (at 296.15 K and 101.325 kPa) was established at National Institute of Metrology (Thailand); NIMT. The standard facility is a mercury-sealed piston prover consisting of three precision- machined glass cylinders. With the positive displacement technique, the facility measures gas flowrate by determining the displaced volume, time, and pressure and temperature of the gas. Flow measurement can be carried out manually or semi-automatically. The electronics were installed in a separate console to minimize the heating effect on the gas temperature. Furthermore, special care was taken in designing the facility to ensure that gas pressure and temperature can be measured as accurate and representative as possible. The relative expanded uncertainty of gas mass flow measurement, evaluated according to ISO GUM, was less than 0.13 % of reading.
- Keywords:
- Piston Prover, Gas Flow Measurement, Uncertainty Analysis
- Download:
- IMEKO-TC9-2010-042.pdf
- DOI:
- -