Many customers are confused about the meanings of the Ex and MA marks. As a professional explosion-proof testing and certification institution, STS Testing (Shenzhen) Co., Ltd. will give a brief explanation to you.

The Ex mark is an abbreviation of the English word "Explosion-proof", meaning explosion-proof. Marking a product with Ex indicates that the product complies with the requirements of explosion-proof standards and is an explosion-proof product. The letters following the explosion-proof mark Ex represent the explosion protection mode, the equipment category of the application site, the temperature class, and the equipment protection category.

In accordance with the requirements of GB/T 3836, the explosion-proof mark of explosion-proof electrical equipment includes:

Explosion protection mode + Equipment category of application site + Temperature class + Equipment protection category

Take the explosion-proof mark Ex db IIC T4 Gb as an example:

Ex indicates that the product is an explosion-proof product;

d b means the explosion protection type is flameproof type, applicable to Zones 1 and 2;

IIC means it is allowed to be used in explosive atmospheres of Group IIC (representative gases are hydrogen and acetylene);

T4 means the surface temperature of the equipment shall not exceed 135℃;

Gb means the protection category of the equipment is "high".

MA is an abbreviation of the initials of "Mei An", standing for Coal Mine Safety. Therefore, the MA mark refers to the Coal Mine Safety Mark. In China, equipment and products used in underground coal mines must obtain the Coal Mine Safety Mark in accordance with the relevant requirements of the National Mine Safety Approval Center, which is a mandatory national certification for safety.