Working principle

The structure and principle of explosion-proof thermistor and assembled thermistor are basically the same. The difference is that the junction box (shell) of explosion-proof products adopts a special explosion-proof structure in the design. The junction box is made of high-strength aluminum alloy die-casting and has sufficient internal space, wall thickness and mechanical strength. The thermal stability of the rubber sealing ring meets the national explosion-proof standards. Therefore, when the explosive mixed gas inside the junction box explodes, its internal pressure will not damage the junction box, and the resulting heat energy cannot diffuse or transmit to the outside.
Due to the use of the above-mentioned explosion-proof special structure, the product fully complies with the explosion-proof temperature range of dIIBT4 or dIICT6. As long as users strictly follow the product usage rules, the product can achieve reliable explosion-proof effect.

Main technical indicators

★ Temperature measurement range and allowable error

Note: "t" represents the absolute value of the measured temperature of the temperature sensing element, and the dual platinum resistance is only supplied to Class B.
Grade A is a special order

★ Nominal pressure

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, as well as the flow rate and type of the measured medium.

★ Thermal resistance insulation resistance

The test voltage for insulation resistance at room temperature can take any value from 10 to 100V DC, and the ambient temperature should be within the range of 15 to 35 ℃, with a relative temperature not exceeding 80%. The insulation resistance value at room temperature should not be less than 100M Ω.

★ Thermal resistance allows current to pass through

The maximum current measured through a platinum resistor shall not exceed 5mA

★ Explosion proof type and level group

Explosion proof level group: dIIBT4 or dIICT4; DIIBT6 or dIICT6
Shell protection level: IP54

Explosion proof Marking Method for Explosion proof Thermistors

★ Explosion proof rating

The explosion-proof rating of explosion-proof thermal resistors is divided into three levels: A, B, and C, based on their maximum safe clearance for explosive gas mixtures.

★ Temperature group

The temperature groups of explosion-proof thermal resistors are divided into six groups, T1 to T6, based on the highest surface temperature of their exposed parts.

Please refer to the example table of explosion-proof thermocouples for the combustible gas, vapor level, and temperature group of explosion-proof platinum resistors.

Product selection

Explosion proof thermistor

Explosion proof armored thermistor

Types and specifications of explosion-proof thermal resistors

Types and specifications of explosion-proof armored thermal resistors

Explosion proof armored thermistor

Install fixed devices

Installation of fixed devices can be divided into three forms: fixed threads, tapered fixed threads, and fixed flanges. The structural dimensions are shown in the table.

Applicable medium for explosion-proof thermistor

★ Explosion proof level and temperature group of flammable gases and vapors: