The Impact of Raw Material Purity on R142b Standard Gas Mixture Preparation

Abstract:

The impact of purity of raw material on the accuracy of gas standard is studied. The R142b with purity of 99.6% and N₂ with purity of 99.996% was used to prepare R142b in N₂ gas standard based on gravimetric method. Results showed that if the impurity in R142b raw material was not dectected, it would cause 0.20-0.23% deviation relative to the reference value; if the uncertainty for impurity in R142b reach to 100%, the uncertainty in each step of dilution was amplified for almost 66.9%-144%, seriously reducing the reliability of the gas standard. Conversely, the neglect of 4.85×10^-5 mol/mol Ar in dilutent gas N₂ would neither significantly affect the mole fraction nor its uncertainty value. These results clarified the importance of purity analysis on standard gas mixture preparation.

• Periodical: Advanced Materials Research (Volumes 1010-1012)
• Pages: 394-398
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1010-1012.394
• Online since: August 2014
• Authors: Zhe Bi, Ze Yi Zhou, Xing Wang, Jie He
• Keywords: Gravimetric Method, Purity, R142b, Standard Gas Mixture, Uncertainty Analysis

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