Two dynamic comparison methods for calibrating the rate of pressure leaks

Abstract In this paper, two dynamic comparison methods are introduced, namely, a dynamic comparison method with a reference leak, and a dynamic comparison method with quantitative gas. The methods can calibrate gas flow rates or leak rates from 1×10 -2 to 1×10 -7  Pa m 3 /s, referenced to a downstream pressure of atmospheric pressure. In the dynamic comparison method with a reference leak, test gas from the unknown pressure leak or from a reference pressure leak is accumulated for different times such that a similar quantity of test gas is introduced into a vessel filled with atmosphere. The mixed gas is then expanded and the expanded gas is introduced into a dynamic flow system. The dynamic balance partial pressure of the test gas is then measured and compared. In the dynamic comparison method with a reference gas, a known quantity of gas is used instead of the accumulated test gas through a reference pressure leak.