WRN-440A flameproof and intrinsically safe thermocouple is a kind of temperature sensor, which is widely used in chemical industry automatic control system. Through the temperature sensor, the temperature parameter of the controlled object can be converted into an electric signal, which is transmitted to the display, record and adjustment instrument , Perform detection, adjustment and control of the system. In chemical plants, the production site is often accompanied by various flammable and explosive chemical gases and vapors. It is very unsafe to use ordinary thermocouples and can easily cause environmental gas explosions. Therefore, explosion-proof or intrinsically safe thermocouples must be used as temperature sensors in these occasions. The explosion-proof or intrinsically safe thermocouples produced by our factory are suitable for dIIBT4～dIICT6, ibIIBT4, iaIIBT4, iaIICT6, and are explosive in temperature groups. In a place where the gas is dangerous. The technical performance of the explosion-proof or intrinsically safe thermocouple produced by our factory meets the technical conditions of JB/T9238-1999 industrial thermocouple GB/T16839-1997, GB/T16839.2-1997 industrial thermocouple indexing table and allowable error, and the product All comply with the general requirements for explosion-proof electrical equipment for explosive environments GB3836.1-2000 and GB3836.2-2000 standards. The national-level instrument and meter explosion-proof safety supervision and inspection station will conduct special verification and approval of product drawings, technical documents, and prototypes. Explosion-proof certificate. At present, the industrial explosion-proof thermocouple produced by our factory has two types: nickel-chromium-nickel-silicon (type K) and nickel-chromium-copper-nickel (type E). Intrinsically safe thermocouples must use intrinsically safe compensation wires. The control range of their distribution parameters: total inductance ≤ 2mH, capacitance ≤ 0.06, and use associated equipment safety barriers. The selection of associated equipment is based on the following principles. Thermocouples (must be insulated ) When equipped with a low internal resistance secondary meter, use MTL760/ac, Z960/ac, LB960/ac safety barriers. For the specific wiring of the safety barrier, please refer to the manufacturer's instructions.