A TECHNIQUE TO IMPROVE LOW LEAK RATE MEASUREMENT WITH A CONSTANT-VOLUME FLOWMETER

F. Boineau, M. D. Plimmer

Abstract

Calibrating leak rates using a constant-volume flowmeter consists in measuring the pressure rise rate produced by the leak throughput in a measurement volume. When the leak rates to be determined are low, the latter should be as small as possible, and since it is composed of dead volumes of the tubing, the valves, the gauge, etc., one needs to determine this dead volume accurately. This paper describes an original and simple technique which provides a relative uncertainty in the calibration of the dead volume of a constant-volume flowmeter (~ 60 cm³) of approximately 0.1 % (<i>k</i> = 1). In turn, the bottom end of the calibration range of the flowmeter has been brought down to about 5 × 10^-8 Pa∙m³∙s^-1.

Keywords

vacuum; low leak rate calibration; constant-volume flowmeter

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IMEKO-TC16-2022-120.pdf

DOI

10.21014/tc16-2022.120

IMEKO TC

TC16 - Pressure and Vacuum Measurement

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