Explosion proof thermocouples - B,S,R,K,N,E,J,T

Industrial Thermocouple Temperature Probe-Explosion proof types is usually connected with display meter,

recording meter and electric regulator, etc. to directly measure temperature of liquid, vapor, gas and solid surface

ranging from 0°C to 1300°C with explosives such as hydrocarbon on production spot.

1. TYPE&MEASURING RANGE

2. TECHNICAL FEATURES

Thermal response time

When the temperature appears step change, the output of thermocouple changes to about 5% of this change. And the time needed is called thermal response time, using T0.5 to express.

Nominal pressure of thermocouple

Generally it refers to static outside pressure the protection tube can stand while not being
broken in operation temperature. In fact tolerant operation pressure is not only related to
protection tube material, diameter and the thickness of wall but also related to its structure,
mounting method, insert length and the flow velocity and type of measured medium.

Minimum insert length of thermocouple

It should be not less than 8 to 10 times of protection tube outlet caliber (special products are exceptional).

Insulation resistance of thermocouple (normal temperature)

The testing voltage of insulation resistance at normal temperature is 500VΦ0V DC. The atmosphere condition measuring insulation resistance at normal temperature should be at

temperature ranging from15-35 °C , with 45% relative humidity and 86- 106 kPa

atmospheric pressure.

For the thermocouple longer than one meter the multiple of its normal-temperature insulation resistance and its length should be not less than 100 Mohm.m.

That is : Rr.L ≥ 100 Mohm.m L> 1m

In the formula: Rr - insulation resistance value of thermocouple at normal temperature,
Mohm

L -Length of thermocouple, m

For the thermocouple shorter than one meter, its insulation resistance value at normal temperature should be not less than 100 Mohm.

Explosion-proof type and class group

Explosion-proof class group: d II BT4 or d II CT4

d II BT6 or d II CT6

Outer shell protection class : IP54

Principle and structure

Explosion-separation thermocouple is the same as assembly type thermocouple in structure and basic principle.The difference is that the junction box of explosion-separation type products uses special explosion-proof structure in design. The junction box is compression casted with high-strengthened Al alloy, having enough inside room, wall thickness and mechanical strength. The thermal stability of rubber sealed loop conforms to national standard of explosion-proof. Therefore, when explosive gases inside junction box explode the inside pressure will not damage junction box, so the heat can not diffuse and the explosion separation could be realised.

3. Types and Specifications of Explosion-separation Type Thermocouple