Gas detectors are divided into fixed gas detectors and portable gas detectors according to detection methods. The fixed gas detector can only be used in a fixed area, can only detect gas leakage in a limited area, and cannot be moved. Portable gas detectors, as their name implies, are portable and can be detected wherever they need to be detected. They are mostly used for limited space exploration.

Electrochemical sensor detection: The electrochemical sensor reacts with the measured gas to generate an electrical signal proportional to the gas concentration to work.An electrochemical sensor consists of a sensing electrode (or working electrode) and a counter electrode, which are separated by a thin electrolytic layer.

Semiconductor gas sensor detection: The semiconductor gas sensor is made by using the oxidation-reduction reaction of gas on the semiconductor surface to change the structure of the sensitive element. The semiconductor gas sensor takes the ceramic tube as the frame, covers a layer of sensitive membrane material, and measures through the gold-plated pins at both ends of the membrane.

Catalytic combustion sensor detection: The components of the catalytic combustion sensor are made of platinum wire and porous ceramic catalytic beads. The principle is to measure the concentration of combustible gas in the environment by using the characteristics of the platinum wire resistance at different temperatures. When the combustible gas enters the catalytic combustion element, under the action of the catalyst, the temperature of the ceramic catalytic bead increases, which drives the temperature of the platinum wire to increase, thereby increasing the resistance. During the measurement, the voltage divided by the measured element also increases accordingly. The concentration of combustible gas can be accurately obtained by calibrating the instrument with pure air and measuring point gas, and the measurement unit is usually% LEL.