Process analysis instrument for measuring gas composition
In many production processes, especially in the presence of chemical reactions, automatic control based on physical parameters such as temperature, pressure, and flow rate is often insufficient. There are many types of gas analyzers due to the diversity of the gases being analyzed and the variety of analysis principles. Commonly used are thermal conductivity gas analyzers, electrochemical gas analyzers and infrared absorption analyzers.
The gas composition is measured based on a change in the amount of ions or a change in current caused by a chemical reaction. In order to improve the selectivity, prevent the measurement electrode surface from being contaminated and maintain the performance of the electrolyte, a diaphragm structure is generally used. There are two types of commonly used electrochemical analyzers: constant potential electrolytic and galvanic cell. The working principle of the constant potential electrolytic analyzer is that a specific potential is applied to the electrode, and the measured gas generates electrolysis on the electrode surface. As long as the potential applied to the electrode is measured, the unique electrolytic potential of the measured gas can be determined, so that the meter has the ability to select and identify the measured gas. Galvani battery analyzer is used to electrolyze the test gas diffused into the electrolyte through the diaphragm, and measure the formed electrolytic current to determine the concentration of the test gas. By selecting different electrode materials and electrolytes to change the internal voltage on the electrode surface, the selectivity of gases with different electrolytic pot