The gas detector with special tubes is a device used to detect the content of a particular gas in the air. For this purpose, the so-called detector tubes are filled with a special agent that changes colour when exposed to a particular gas. Detector tubes can detect and determine the concentration of gases such as carbon monoxide, carbon dioxide, hydrogen sulphide, etc. The process of testing the content of a given gas in the air involves placing a detector tube that is exposed at both ends into the detector's socket, and then squeezing the pump to draw air from the environment. The number of squeezes depends on the type of detector tube. The tube changes colour depending on the type of tube and the type of gas being tested. There is also a scale on the tube that allows you to read the concentration of a particular gas in the air being tested. The scale is related to the intensity of the colouration of the agent inside the tube.