WRN-240 explosion-proof thermocouple?

The WR series industrial explosion-proof intrinsic safety thermocouple is a temperature sensor widely used in chemical industry control systems. Through the temperature sensor, the temperature parameters of the controlled object can be converted into electrical signals and transmitted to display, record, and regulate instruments to detect, regulate, and control the system. In chemical plants, various flammable and explosive chemical gases and vapors are often present on the production site. Using ordinary thermocouples is very unsafe and can easily cause environmental gas explosions. Therefore, in these situations, explosion-proof or intrinsic safety thermocouples must be used as temperature sensors. The WRN2-240A dual explosion-proof intrinsic safety thermocouple is suitable for use in places with explosive gas hazards within the temperature group range of dIIBT4 to dIICT6, ib Ⅱ BT4, ia Ⅱ BT4, and ia Ⅱ CT6.

Main technical parameters

Measurement range: 0-800 ℃

◆ Division number: K division

Accuracy level: Level I (± 1.5 ℃ or ± 0.004 | t |) Level II (± 2.5 ℃ or ± 0.0075 | t |)

◆ Thermocouple category: Double branch nickel chromium nickel silicon

◆ Material of protective tube: stainless steel 304, 321, 316, etc

◆ Depth of thermocouple insertion: l=100mm or not less than 6-10 times the diameter of its protective tube (excluding special products)

◆ Thermal response time: T0.5 ≤ 90S (the time required for the output of the thermocouple to change to 50% of the step change when the temperature undergoes a step change is called the thermal response time, represented by T0.5).

◆ Nominal pressure: 6MPa (generally refers to the static external pressure that the protective tube can withstand without breaking at room temperature, and the test pressure is generally 1.5 times the nominal pressure. In fact, the allowable nominal pressure is not only related to the material, diameter, and wall thickness of the protective tube, but also to its structural form, installation method, insertion depth, and the flow rate and type of the measured medium).

◆ Thermocouple insulation resistance: The test voltage for insulation resistance at room temperature is DC 500 ± 50V. The atmospheric conditions for measuring insulation resistance at room temperature are: temperature of 15-35 ℃, relative humidity of 45%, and atmospheric pressure of 86-106kPa.

For thermocouples with a length exceeding 1 meter, the product of their insulation resistance at room temperature and their length should not be less than 100M Ω. m.

For thermocouples with a length of 1 meter or less, their insulation resistance at room temperature should not be less than 100M Ω.

◆ Insulation resistance of armored thermocouple (insulated type): When the ambient temperature is 20 ± 15 ℃ and the relative humidity is not greater than 80%, the insulation resistance between the thermoelectric electrode and the outer sleeve should be greater than or equal to 100M Ω. m (i.e. the product of the insulation resistance at room temperature and the length of the armored thermocouple), and the test voltage is 500V DC.

Explosion proof type

◆ Explosion proof type and level group

Explosion proof level group: dIIBT4 or dIICT4; DIIBT6 or dIICT6

Intrinsic safety group: ia Ⅱ BT4 or ia Ⅱ CT4 (multi pair); Ia Ⅱ BT6 or ia Ⅱ CT6 (multi pair)

◆ Shell protection level: IP65

Explosion proof mark, category, level, and temperature group description:

Explosion proof mark: Explosion proof type (d); Intrinsic safety type (ia)

Electrical equipment category: Class I - Electrical equipment used underground in coal mines; Class II - Factory Electrical Equipment

Explosion proof level: The explosion-proof level of explosion-proof and intrinsic safety thermocouples is suitable for explosive gas mixtures with very large safety clearances or very small ignition current ratios of A B,C, Level three.

◆ Temperature group: The temperature groups of explosion-proof and intrinsic safety thermocouples are divided into six groups according to the allowable very high surface temperature of their exposed parts, T1~T6 (T1=450 ℃, T2=300 ℃, T3=200 ℃, T4=135 ℃, T5=100 ℃, T6=85 ℃).