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A note on flow rate and leak rate units



Charles D. Ehrlich


The confusion in the literature and in the laboratory surrounding the terminology and units of gas flow rates, particularly as applied to calibrated leak artifacts, has prompted this discussion of leak rate units. Special attention is paid to conflicting usages of the term "throughput," and how this frequently leads to the loss of crucial information about the gas temperature and hence the true gas flow rate. The advantages of expressing leak rates in "mol/s," avoiding the complications of both the explicit mention of temperature in the unit and the need for agreement on "standard" temperature and pressure, are also discussed.
Journal of Vacuum Science & Technology A


Ehrlich, C. (1986), A note on flow rate and leak rate units, Journal of Vacuum Science & Technology A, [online], (Accessed April 19, 2024)
Created April 28, 1986, Updated November 10, 2018