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Time dependence in “static” measurements of vapor pressure



Robert F. Berg


The static method for measuring vapor pressure assumes that the sample is pure and that its temperature is steady and uniform. In practice, the measured pressure may be time dependent due to evaporative cooling after pumping on the sample, transpiration of the sample in a temperature gradient, or diffusion of an impurity out of the sample. An impurity cannot be avoided if the sample is decomposing. This article discusses causes of time dependence, and it includes an analysis that obtained the vapor pressure from the time-dependent pressure of a decomposing sample.
Journal of Chemical and Engineering Data


cyclic pumping, decomposition, diffusion, evaporative cooling, time-dependent pressure, transpiration, vapor pressure


Berg, R. (2015), Time dependence in “static” measurements of vapor pressure, Journal of Chemical and Engineering Data, [online], (Accessed May 27, 2024)


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Created November 17, 2015, Updated November 10, 2018