Electrochemical gas analysis instruments
A type of chemical gas analysis instrument. It measures the gas components by detecting the changes in the amount of ions or current caused by chemical reactions. To improve selectivity, prevent the measurement electrode surface from contamination and maintain the performance of the electrolyte, a diaphragm structure is generally used. Common electrochemical analysis instruments include potentiometric electrolytic type and Galvanic cell type. The working principle of the potentiometric electrolytic type analyzer is to apply a specific potential to the electrode, and the measured gas will undergo electrolysis on the electrode surface. By measuring the potential applied to the electrode, the unique electrolytic potential of the measured gas can be determined, thereby enabling the instrument to have the ability to identify the measured gas. The Galvanic cell type analyzer electrolyzes the measured gas through the diaphragm and measures the formed electrolytic current to determine the concentration of the measured gas. By selecting different electrode materials and electrolyte to change the internal voltage on the electrode surface, selectivity for gases with different electrolytic potentials can be achieved.
Infrared absorption analyzer
An analyzer that works based on the characteristic that different component gases selectively absorb different wavelengths of infrared rays. Measuring this absorption spectrum can determine the type of gas; measuring the absorption intensity can determine the concentration of the measured gas. Infrared analyzers have a wide range of applications, not only for analyzing gas components but also for analyzing solution components, and they have high sensitivity, rapid response, and can provide online continuous indication, and can also form a regulation system. The detection part of the commonly used infrared gas analysis instruments in industry consists of two parallel and structurally identical optical systems.
In addition, gas analysis instruments include the following technical types: laser spectroscopy technology including tunable semiconductor laser absorption spectroscopy (TDLAS) and laser Raman spectroscopy (LRD) [1]. Chromatography technology such as portable gas chromatograph (Portable GC) [2]. Multi-parameter detection technology such as four-in-one gas detector [9]. Other technical principles include thermal conductivity analyzer, paramagnetic oxygen analyzer [6], Fourier transform infrared (FTIR) spectrometer [4-5], non-dispersive infrared spectroscopy (NDIR), and ultraviolet differential absorption spectroscopy (UV-DOAS) [1].