Views: 0 Author: Site Editor Publish Time: 2023-04-03 Origin: Site
With the application and development of the electronic scale, the weighing sensor has kept pace with the times since its appearance, and has made great progress in innovation and development. However, due to the explosion risk of some flammable and explosive materials in the weighing process, explosion-proof load cells came into being, and their functions are also welcomed by most people. Explosion proof load cell is a device that uses the physical characteristics of temperature related materials or components to convert temperature changes into electricity changes. The commonly used explosion-proof weighing sensors in measurement include thermocouple and thermal resistance. Thermocouples convert temperature change into potential change, while thermal resistors convert temperature change into resistance value change. The materials selected for the temperature sensing elements of explosion-proof load cells shall meet the following requirements: the resistance temperature coefficient of the materials shall be large, the explosion-proof load cells shall be within the temperature measurement range, the physical and chemical properties of the materials shall be stable, the Mihu explosion-proof load cells shall be within the temperature measurement range, shall be maintained in Changshu, have a large resistivity P, and the explosion-proof load cells shall have good reproducibility and be easy to copy. Materials suitable for the above conditions include platinum, copper, iron and nickel. Next, we will introduce the application of explosion-proof load cells:
1: Intrinsically safe electronic weighing system
The intrinsically safe electronic weighing system has two explosion-proof types: one is an independent intrinsically safe explosion-proof system. In this system, all circuits of explosion-proof load cells, explosion-proof junction boxes, intrinsically safe weighing instruments and other equipment are placed in flammable and explosive hazardous areas, and the circuits in the system are intrinsically safe; The other is a hybrid intrinsically safe explosion-proof system. In this system, explosion-proof load cells and explosion-proof junction boxes are placed in dangerous areas, and the safety clearance between weighing instruments and explosion-proof junction boxes is placed in safe areas together with weighing instruments.
2: Explosion proof junction box
When multiple IA, IB intrinsically safe or D explosion-proof load cells are used to assemble the electronic scale in parallel, the parallel connection box is related to the intrinsically safe circuit, it is not an intrinsically safe circuit, and must be designed and manufactured into an explosion-proof structure, which is applicable to the explosion-proof equipment in Zone 1 and Zone 2 of flammable and explosive hazardous areas. The junction box is made of steel materials. The roughness of the flameproof surface, the small effective length L of the joint surface and the gap, and the large diameter difference of the flameproof joint surface of the shaft and shaft hole must meet the flameproof requirements specified in the National Standard for Flameproof Electrical Equipment (GB3836.2-2010).
3: Intrinsically safe explosion-proof electronic scale
Intrinsically safe explosion-proof electronic scale adopts the principle of explosion-proof weighing sensor, so that the sensor will not produce dangerous detonating source and detonate explosives in case of fault short circuit. Intrinsically safe type means that all circuits in the equipment will not produce electric sparks during normal operation, or the energy generated by electric sparks and thermal effects is insufficient to ignite explosive substances. All circuits include load cells, so explosion-proof load cells are required in intrinsically safe explosion-proof scales.