Each sensor in the gas detector will have a corresponding gas. When choosing a gas sensor, it is necessary to fully understand whether detecting other gases will cause significant interference to the sensor. This can effectively ensure the accuracy of gas detectors in detecting special gases.

Stimulating gases exist in many industrial production processes, such as welding, electroplating, smelting, chemical, petroleum and other industries. Most of these gases are corrosive and can cause acute poisoning when entering the human body through the respiratory tract. The common characteristic of the toxic effects of irritating gases on the body is their varying degrees of irritation to the eyes, respiratory mucosa, and skin. Generally, local damage is the main cause, but it can also cause systemic reactions. The steam of "three acids" can irritate the respiratory mucosa and cause skin burns; Long term exposure to low concentration acid mist can also stimulate teeth and cause tooth corrosion. Chlorine gas, ammonia gas, sulfur dioxide, sulfur trioxide and other substances are highly soluble in water and can easily cause damage to wet areas. If these gases are inhaled, they will dissolve in the upper respiratory mucosa, directly stimulating the mucosa, causing congestion, edema, increased secretion, chemical inflammatory reactions, and symptoms such as runny nose, itching in the throat, and coughing. Nitrogen oxides, phosgene, and other substances have low water solubility and rarely cause hydrolysis when passing through the upper respiratory mucosa, resulting in mild mucosal irritation; But they can continue to infiltrate the bronchi and alveoli, gradually interact with the water on the mucosa, and have a positive effect on lung tissue. Generate strong stimulation and corrosive effects, and in severe cases, pulmonary edema may occur.

It is generally believed that the definition of a gas detector is based on the classification of the detection object, that is, any sensor used to detect gas composition and concentration, whether it is a physical or chemical method, is called a gas sensor. For example, sensors that detect gas flow are not considered gas sensors, but thermal conductivity gas analyzers are important gas sensors, although they sometimes use generally consistent detection principles.