Determining Uncertainties of Relative Humidity, Dew/Frost-Point Temperature, and Mixing Ratio in a Humidity Standard Generator

摘要

This paper presents an extension of the authors previous work on determining the uncertainty of dew/frost-point temperature to cover uncertainties of both relative humidity and mixing ratio in a two-pressure and/or two-temperature type precision humidity generators which are used by most of national standards laboratories in the world. Three analytical equations, based on the thermodynamic relations governing such generators are derived to express the expanded uncertainties of the relative humidity, dew/frost-point temperature, and mixing ratio, respectively.