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Two Primary Standards for Low Flows of Gases



Robert F. Berg, S A. Tison


We describe two primary standards for gas flow in the range from 0.1 to 1000 mol/s. (1 mol/s =1.3448 standard cubic centimeters per minute.) The first standard is a volumetric technique in which measurements of pressure, volume, temperature, and time are recorded while gas flows in or out of a stainless steel bellows at constant pressure. The second standard is a gravimetric technique. A small aluminum pressure cylinder supplies gas to a laminar flow meter, and the integrated throughput of the laminar flow meter is compared to the weight decrease of the cylinder. The two standards differ by approximately 0.06%. Although this exceeds the combined standard uncertainty of 0.04%, it suggests that the error of both standards is less than 0.06%.
International Symposium on Fluid Flow Measurement
109 No. 4


flow meter, gas flow, gravimetric, laminer flow meter, primary standard, volumetric


Berg, R. and Tison, S. (2002), Two Primary Standards for Low Flows of Gases, International Symposium on Fluid Flow Measurement, [online], (Accessed April 22, 2024)
Created September 1, 2002, Updated February 17, 2017