Low-Gas-Flow Proficiency Testing

摘要

The measurement of small gas flows is important for a number of industrial processes and for proper operation of many internal combustion engines. Because of the wide demand for calibration of low-gas-flow measurement instruments, many companies maintain primary flow standards. The uncertainties of the primary flow standards are derived on a model of the calibration system and the uncertainties in the measured parameters (pressure, temperature, etc.). To ascertain whether measurements are being made within the estimated uncertainty, measurement assurance programs are often employed. Alternately, a proficiency test may be used for the same purpose. This paper describes low-gas-flow proficiency testing performed by NIST over the range of 10~(-6) mole/s to 10~(-3) mole/s ～(1 to 1000)sccm.