(2) Flameproof explosion-proof type: refers to the combustible gas alarm shell can withstand the combustible mixture that penetrates into the shell through any joint surface or structural gap of the shell to explode inside without damage, and it will not cause the ignition of an explosive atmosphere formed by 1 or more gases or vapors. (Note: Explosion-proof type of flameproof enclosure is usually called flameproof type, indicated by letter "d")

(3) Intrinsically safe explosion-proof type: it is an intrinsically safe circuit in which all circuits inside the combustible gas alarm are formed by any electric spark or any thermal effect generated under the specified conditions of the standard (including normal operation and specified fault conditions), which cannot ignite the specified explosive gas environment, denoted by the letter "I."Iɑ" grade electrical equipment is an intrinsically safe electrical equipment that cannot cause ignition under normal operation and application of a fault and any combination of two fault conditions. "ib" grade electrical equipment is an intrinsically safe electrical equipment that cannot cause ignition under normal operation and application of a fault condition.

2. Device Category

(1) Class I: coal mine underground electrical equipment.

(2) Class II: Electrical equipment used in explosive gas environments other than coal mines.

(3) Class II flameproof "d" and intrinsically safe "I" electrical equipment is divided into classes IIA, IIB, and IIC.

(4) Electrical equipment for combustible dust environment is divided into: type A dust-tight equipment; Type B dust-tight equipment; Type A dust-tight equipment; Type B dust-tight equipment.

3. gas group

gas group refers to the explosive transmission capacity of explosive gas mixtures, it marks the degree of explosion danger, and the greater the explosive transmission capacity of the explosive mixture, the higher the risk. The explosive transmission capacity of an explosive mixture can be expressed by a larger test safety gap. At the same time, the degree of difficulty of explosive gas, liquid vapor and mist being ignited also marks the degree of explosion risk, which is expressed by the minimum ignition current ratio. Class II flameproof electrical equipment or intrinsically safe electrical equipment is further divided into classes IIA, IIB and IIC according to its larger test safety gap or minimum ignition current ratio suitable for explosive gas mixtures.

4. temperature groups

the temperature group refers to the temperature limit at which the ignition temperature of an explosive gas mixture can be ignited.

To sum up, it is some of the contents contained in the explosion-proof requirements of combustible gas alarm, hoping to be helpful to everyone. If you want to know more about combustible gas alarm, please continue to pay attention to Yiyuntian.