As a temperature sensor, the resistance of thermal resistor can be varied under the change of temperature. WMTR-Ex thermal resistor is used to measure the temperature of liquid, steam, gas and the solid surface ranging -200°C to 500°C. It is noted for their flexibility, wear resistance, vibration resistance and high temperature resistance. The outer protective tube of the armored thermo element is made of stainless steel and in which high density oxide is used as the insulating layer, it is pollution resistance and enough mechanical strength, in order to meet the adverse circumstances.

For various inflammable, explosive chemical gas, steam often occur on production site in chemical factory, it is unsafe to use normal thermal resistor, which is easy to cause atmosphere explosion. Therefore, explosion isolation thermal resistor shall be used as temperature sensor under these cases, under the situation where with explosive gas within the temperature group dIIBT4~dIICT6. WMTR-Ex Ex-proof thermal resistor is using special explosion prevention structure and ex-proof case which is made of aluminum alloy with high mechanical strength. Therefore, even if explosive mixed gas in joint box is exploded, its thermal energy caused during it cannot be spread out.

WMTR-Ex thermal resistor can be made by assembly structure or sheathed structure. In comparison with assembly type, the sheathed is with small diameter, easy to bend, perfect vibration endurance, suitable for the place where assembly type is not suitable.

Technical specification

Resistance value at 0C for thermal resistance temperature sensitive components (R0)

Graduating number Pt100:

Level A  R0 ＝100±0.06Ω

Level B  R0 ＝100±0.12Ω

Heat response time

Nominal pressure

In general, it indicates the static external pressure undertaken by protection tube at normal temperature, without break occurred. Normal trial pressure is 1.5 times of nominal pressure. In fact, allowed nominal pressure is not only related with protection material, diameter, wall thickness, also with structure, installation method, probing depth, and flow and type of measured media.

Insulated resistance

Trial voltage for insulated resistance at normal temperature can be selected as any value within 10~100V, and atmosphere temperature shall be within 15 ~ 35℃. Relative humidity shall be less than 80%. Insulated value at normal temperature shall be greater than 100MΩ.

Explosion prevention level

Explosion prevention level of explosion isolation thermal resistor can be divided into level A, B, C according to max safe clearance used in explosive air.

Electrical equipment can be divided into 2 types:

Type I - electrical equipment used in coal mining well;

Type II - electrical equipment used by factory

Temperature group of explosion isolated thermal resistor, max surface temperature can be divided into T1 ~ T6 groups.

Protection grade: Ex dIIBT4~Ex dIICT6