WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple

                                        WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple

Overview

WRR-120 WRR2-120 WRR-121 WRR2-121 singel double platinum rhodium thermocouple can directly measure the temperature of liquid, gas, steam and solid surface in the range of 0 ℃ ~ 1800 ℃ in various industrial production processes, convert the temperature signal into thermoelectric EMF signal, and convert it into the temperature of the measured medium through secondary instrument. In practical application, thermocouple has many structural modes, but its working principle is the same. Because of its simple structure, convenient manufacture, wide temperature measurement range, high precision, small inertia and convenient remote transmission of output signal, it has been widely used in industrial production. Platinum rhodium thermocouple is a precious metal thermocouple. The diameter of the couple wire is specified as 0.5mm, and the allowable deviation is -0.015mm. The nominal chemical composition of the positive electrode is platinum rhodium alloy, in which the rhodium content is 30%, the platinum content is 70%, the negative electrode is platinum rhodium alloy, and the rhodium content is 6%, so it is commonly known as double platinum rhodium thermocouple. The maximum long-term operating temperature of the thermocouple is 1600 ℃, and the maximum short-term operating temperature is 1800 ℃.

Working priciple of WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple

The basic principle of thermocouple temperature measurement is that two different material conductors form a closed loop. When there is a temperature gradient at both ends, there will be current passing through the loop. At this time, there is electromotive force - thermoelectric electromotive force between the two ends, which is the so-called Seebeck effect. The homogeneous conductor with two different components is a thermoelectric electrode. The higher temperature end is the working end and the lower temperature end is the free end. The free end is usually at a constant temperature. According to the functional relationship between thermoelectric EMF and temperature, a thermocouple graduation table is made; The graduation table is obtained when the free end temperature is 0 ℃, and different thermocouples have different graduation tables.

Features of WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple

Platinum rhodium thermocouple has the advantages of the highest accuracy, the best stability, wide temperature measurement range, long service life and high temperature measurement upper limit. It is suitable for oxidizing and inert atmosphere, and can also be used in vacuum for a short time, but it is not suitable for reducing atmosphere or atmosphere containing metal or non-metal vapor. One obvious advantage of type B thermocouple is that it does not need compensation wire for compensation, because the thermal potential is less than 3 in the range of 0 ~ 50 ℃ μ V。

Disadvantages: the disadvantages of platinum rhodium thermocouple are thermal potential, small thermoelectric potential rate, low sensitive reading, reduced mechanical strength at high temperature, very sensitive to pollution and expensive precious metal materials, so the one-time investment is large.

Main tech data of  WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple

measurement range: 0-1600-1800 ℃

graduation number: B graduation

accuracy grade: Grade I (± 1.5 ℃ or ± 0.0025 T)

thermocouple type: platinum rhodium 30 - platinum rhodium 6

junction box type: wrr-120 is splash proof junction box, wrr-130 is waterproof junction box

protective tube material: corundum

diameter of protective tube: 16mm

insertion depth of protective tube: l = 200-1200mm

installation method: no fixed type

thermal response time: t0 5 < 150s (in case of step change in temperature, the time required for the output of thermocouple to change to 50% of the step change, represented by t0.5)

nominal pressure of thermocouple: normal pressure (generally refers to the static external pressure that the protective tube can withstand without rupture)

thermocouple nominal flow rate: no flow rate

insulation resistance of thermocouple: the test voltage of insulation resistance at room temperature is DC 500V ± 50V, the atmospheric conditions are temperature 15 ~ 35 ℃, relative humidity 45%, atmospheric pressure 86 ~ 106kpa, and its insulation value at room temperature shall be ≥ 100m Ω.

executive standard: JB / t9238-1999

Note: Any special design or question of  WRR-120 WRR2-120 WRR-121 WRR2-121 Pt-Rh thermocouple,kindly contact the manufacturer for more details.