The standards for explosion-proof certification in our country are synchronized with IEC certification. The officially approved explosion-proof certification by the state is divided into eight different forms, namely explosion-proof certification (d), increased safety explosion-proof certification (e), intrinsic safety explosion-proof certification (intrinsic safety explosion-proof certification) (i), positive pressure explosion-proof certification (p), oil filled explosion-proof certification (o), sand filled explosion-proof certification (q), non spark explosion-proof certification (n), and sealed explosion-proof certification (m). In addition, there are two types of explosion-proof certifications: special explosion-proof and dust explosion-proof. Below, Shenzhen Zhongnuo Testing Technology Co., Ltd. provides an interpretation of the current national explosion-proof standards and certification types as of 2018.

In automation instrument equipment, the first three types of explosion-proof certification widely used in countries around the world are explosion-proof type (d), increased safety type (e), and intrinsic safety type (i).

1. Explosion proof certification for explosion-proof electrical equipment (d)

Explosion proof certification for electrical equipment with explosion-proof enclosures refers to the sealing of components that can ignite explosive mixtures in an enclosure that can withstand the explosive pressure of the internal explosive mixture and prevent the transmission of explosion to the surrounding explosive mixture.
2. Explosion proof certification for increased safety electrical equipment (e)

Electrical equipment that does not produce sparks or hazardous temperatures that ignite explosive mixtures under normal operating conditions, and measures are taken to improve its safety level in structure to avoid ignition under normal and specified overload conditions, can obtain increased safety electrical equipment explosion prevention certification.
3. Intrinsically safe electrical equipment explosion-proof certification (i)

Sparks or thermal effects generated during normal operation or under standard test conditions cannot ignite electrical equipment with explosive mixtures. The explosion-proof certification for intrinsically safe electrical equipment and its associated equipment is divided into two levels, IA and IB, based on the place of use and safety level of intrinsically safe circuits.
IA level explosion-proof certification: Electrical equipment that cannot ignite explosive gas mixtures during normal operation, one or two faults.
IB level explosion-proof certification: Electrical equipment that cannot ignite explosive gas mixtures during normal operation or in the event of a malfunction.

As of 2018, the current national explosion-proof standard