GB/T 42426-2023Chemicals—Vapor pressure test (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents" drafting.

1 Scope

This document describes the dynamic method, the static method, the liquid vapor pressure gauge method, the percolation method---vapor pressure equilibrium, the percolation method---Knudsen cell, percolation method Out method --- Determination methods of isothermal thermogravimetry, gas saturation method and rotary method for chemical vapor pressure test.

This document is applicable to the determination of the vapor pressure of solids and liquids at 10-10Pa~105Pa, and is used for samples that are not decomposed under the determination conditions.

If the above conditions are not applicable, please refer to the vapor pressure estimation method in Appendix A.

The comparison of vapor pressure test methods is shown in Table 1.

Test Method Solid Substance Liquid Substance Estimated Repeatability Estimated Reproducibility Recommended Range Low melting point for dynamic method 25% max 1%~5% 25% max 1%~5% 103Pa~2 x 10^3Pa 2 x 10^3Pa~105Pa Static method is suitable for 5%~10% 5%~10% 10Pa~105Pa 10-2Pa~105Paa The liquid vapor manometer method is suitable for 5%~10% 5%~10% 102Pa~105Pa Exudation method---applicable to vapor pressure balance 5%~20%, maximum 50% 10-3Pa~1Pa Seepage method --- Knudsen pool is suitable for 10%~30% - 10-10Pa~1Pa Exudation method --- isothermal thermogravimetry is suitable for 5%~30%, maximum 50% 10-10Pa~1Pa The gas saturation method is suitable for 10%~30% and the maximum is 50% 10-10Pa~103Pa The rotary method is suitable for 10%~20% - 10-4Pa~0.5Pa a Use a capacitance manometer.

Among them, the liquid vapor pressure gauge method is suitable for the determination of vapor pressure of liquid and solid samples, but not for multi-component samples.

The sample test error of non-native impurities is small, and the pressure measurement range recommended by this method is 102Pa~105Pa.

2 Normative references

This document has no normative references.

3 Terms and Definitions

The following terms and definitions apply to this document.