Divided into three categories

Category I: Electric equipment under the coal mine;

Class II: Electric equipment for all explosive gas environment except coal mines and under wells.

Class Ⅱ can be divided into Class IIA, ⅡB, and Ⅱc. The device marked ⅡB can be suitable for the use conditions for ⅡA devices; Ⅱc can be applicable to the use conditions of ⅡA and Ⅱb.

Class III: Explosive dust environment electrical equipment other than coal mines.

Class IIIA: Flying Flying Flying; Class IIIB: Non -conductive dust; Class IIIC: conductive dust.

Supreme surface temperature: When the electrical equipment works under the most unfavorable operating conditions within the specified range, it may cause the maximum temperature reached by any component of the electrical equipment ignited by the surrounding explosive environment. The highest surface temperature should be lower than the flammable temperature.

For example: The ignition temperature of the explosion -proof sensor environment of the environment is 100 ° C, so in the worst working state, the maximum surface temperature of any component should be lower than 100 ° C.