An automatic digital tensimeter with a membrane zero-manometer

Abstract

An automatic setup for measuring vapor pressure and its temperature dependence in a closed volume is designed. The setup can be used to investigate chemical equilibria in both condensed phase–vapor and homogeneous gas-phase systems, along with the kinetics of irreversible processes with the evolution of gas substances. The digital tensimeter offers an improved version of static tensimetry with a membrane zeromanometer. In contrast to conventional optical methods for recording the position of a zero-manometer, an approach based on the Hall effect is used. Automation of the experiment and data acquisition greatly increases the number of experimental points and reduces the errors related to measurements. With processes of irreversible hydrogen release, the method detects hydrogen with a precision of 2 × 10⁻⁶ g, remarkably exceeding the possibilities of thermogravimetric methods.