With the advancement of technology, the application of touch screens is becoming increasingly widespread. Especially in places with explosive hazards such as oil and gas, chemical, pharmaceutical, and military industries, various touch screen electronic and electrical products can be seen. These types of places require electrical equipment to pass relevant tests according to national explosion-proof standards and obtain corresponding explosion-proof certificates. Taking touch screen instrument boxes as an example and obtaining explosion-proof certificates, Zhongnuo Testing will briefly describe the key and difficult points of how to transform an ordinary product into an explosion-proof product and successfully obtain the explosion-proof certificate.

The production of the shell in explosion-proof renovation is a major difficulty. The shell of the product itself definitely does not meet the requirements and needs to be replaced as a whole. A flameproof shell that meets the size requirements should be designed. However, due to the large number of ports and touch screen in the product, there are several design difficulties that need to be solved. The specific difficulties are as follows:

Firstly, the touch screen is a crucial component as the explosion-proof casing must withstand significant explosive pressure. The touch screen can only be equipped with a regular display screen, which cannot serve as a part of the casing. Therefore, an observation window must be installed on the casing(The material should be tempered glass with a certain thickness)The observation window and the casing should be sealed with glue and mechanically compressed. As for the touch screen, if it needs to be operated, an explosion-proof button should be installed on the casing to achieve this;

Secondly, the communication unit/The interface processing method for this product involves multiple communication channels that require external connections. In the field of explosion-proof, the use of aviation plugs is not allowed and must be replaced with explosion-proof dedicated introduction devices. These introduction devices need to reserve number positions on the housing, and the quantity and size are determined according to actual requirements. Some communications can be achieved through the use of multi-core wires(Can distinguish pins to achieve)；

Furthermore, the antenna part is wireless transmission, and the power of this part needs to be limited. Firstly, the energy needs to be limited, and the circuit of the antenna needs to be reviewed. If the circuit design needs to be modified and the difficulty of rectification cannot meet the explosion-proof requirements, the antenna function should be considered to be removed;

Finally, there are other issues that need to be rectified according to the recommendations of the explosion-proof engineer.

The instrument box produced and certified according to explosion-proof requirements is called an explosion-proof instrument box (with operation button type), which is mostly made of aluminum alloy die-casting or steel plate welding. The surface is shot blasted at high speed and then electrostatically sprayed, with a beautiful appearance. The products are mostly explosion-proof structures, which can accommodate various explosion-proof instruments such as voltage meters, current meters, digital meters, temperature controllers, tachometers, flow meters and other display instruments that need to be operated.

Explosion proof instrument box(Type with operation buttons)Applicable to1District2Dangerous areas in the district; Applicable toⅡA、ⅡB、ⅡCclassT6Explosive gas environment in the following groups; Widely used in hazardous areas such as petroleum, chemical, offshore platforms, military, and ports for communication50HzRated voltage380VIt is used for the opening and closing of power branches in the circuit, and has overload and short circuit protection functions.

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