WRN-625 Welding Fixed Cone Protective Tube Thermocouple

WRN-625 welded fixed conical protection tube thermocouple is commonly used as a temperature sensor in conjunction with display instruments, recording instruments, and electronic regulators. It can directly measure the surface temperature of liquids, vapors, gases, and solids within the range of 0 ℃ to 1800 ℃ in various production processes.

According to regulations, our factory has been producing platinum rhodium with IEC international standard division numbers since 1987₃₀-Platinum rhodium₆Platinum rhodium₁₀-Platinum, nickel chromium nickel silicon, nickel chromium copper nickel, copper copper nickel, iron copper nickel and other types of thermocouples shall comply with JB/T3238-1999 standard.

Working principle: The working principle of a thermocouple is that two conductors with different compositions are welded at both ends to form a circuit. The direct temperature measuring end is called the measuring end, and the wiring terminal end is called the reference end. When there is a temperature difference between the measuring end and the reference end, a thermal current will be generated in the circuit. When connected to a display instrument, the instrument will indicate the corresponding temperature value of the thermoelectric potential generated by the thermocouple.

The thermoelectric potential of a thermocouple will increase as the temperature at the measuring end rises. The magnitude of the thermoelectric potential is only related to the material of the thermocouple conductor and the temperature difference between the two ends, and is independent of the length and diameter of the thermoelectric electrode.

Prefabricated thermocouples are mainly composed of a junction box, protective tube, insulating sleeve, terminal block, and thermoelectric electrode, and are equipped with various installation and fixing devices.

Temperature measurement range and allowable error

Note "t" refers to the measured temperature of the temperature sensing element

Thermal response time

When there is a step change in temperature, the output of the thermocouple changes to 50% of the change, and the time required is called the thermal response time, denoted by T_0.5express.

Thermocouple nominal pressure

Generally refers to the static external pressure that the protective tube can withstand at room temperature without breaking. In fact, the allowable working pressure is not only related to the material and diameter 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.

Small insertion depth of thermocouple

It should not be less than 8-10 times the outer diameter of its protective tube (except for special products).

Thermocouple insulation resistance (at room temperature)

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

a. For thermocouples over 1 meter in length, the product of their insulation resistance at room temperature and their length should not be less than 100

即Rr. L≥100 MΩ。 M L＞1m

In the formula, the insulation resistance value of Rr thermocouple at room temperature is M Ω

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

Upper limit temperature insulation resistance

The insulation resistance of the upper limit temperature of the thermocouple should not be less than the following specifications:

Product selection information:

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