本文叙述用重量法测量气体中水蒸汽含量的原理、装置及测量程序。对影响测量的诸因素进行分析并给出测量的准确度。在质量混合比为(0.2—15)mg/g湿度范围内,测量的最大不确定度为0.32％。这种方法优于目前已知的其它各种湿度测量方法,可作为湿度测量的基准方法。 This article describes the principle, apparatus, and measurement procedures for measuring the amount of water vapor in a gas by gravimetry. The factors that influence the measurement are analyzed and the accuracy of the measurement is given. The maximum uncertainty of measurement was 0.32% at a mass mixing ratio of (0.2-15) mg / g humidity. This method is superior to other various humidity measurement methods known so far and can be used as a reference method for humidity measurement.