Infrared gas analyzer uses infrared to analyze the body. It is based on the different concentrations of the components to be analyzed, the absorbed radiant energy is different, and the remaining radiant energy makes the temperature in the detector rise differently, and the pressure on the two sides of the moving film is different, thereby generating an electrical signal of the capacitive detector . In this way, the infrared gas analyzer can indirectly measure the concentration of the component to be analyzed.
Infrared gas analyzer is based on Beer’s law. Assume that the measured gas is an infinitely thin plane. Infrared light of intensity k penetrates it vertically, and the amount of energy attenuation is: I = I0e-KCL (Beer’s Law)
In the formula: I–the intensity of radiation absorbed by the medium;
I0–the radiation intensity before infrared rays pass through the medium;
K–the absorption coefficient of the component to be analyzed on the radiation band;
C–gas concentration of the component to be analyzed;
L–length of air chamber (measured thickness of gas layer)
For a manufactured infrared gas analyzer, the measurement components have been determined, that is, the absorption coefficient k of the radiation component to be analyzed is constant; the infrared light source has been determined, that is, the radiation intensity I0 before the infrared passes through the medium is constant; The chamber length L is constant. From Beer’s law, it can be seen that by measuring the attenuation I of the radiant energy, the concentration C of the component to be analyzed can be determined.