Prefabricated thermistor

Prefabricated thermistor temperature sensors are matched with display instruments to measure the temperature of liquid, gas media, and solid surfaces within the range of -200-600 ℃. They are widely used in industrial sectors and technological fields such as petroleum, chemical, mechanical, metallurgical, power, textile, food, atomic energy, aerospace, etc. Prefabricated thermistors are usually composed of temperature sensing elements, installation and fixing devices, and junction boxes and other main components.

Optional models

Pt100 type, Pt1000 type, Cu50 type

Main technical indicators for assembling thermistor

Working principle of assembling thermistor

Thermistor measures temperature by utilizing the characteristic that the resistance of a substance changes with temperature. The heated part (temperature sensing element) of a thermal resistor is uniformly wound around a skeleton made of insulating material with thin metal wires. When there is a temperature gradient in the measured medium, the measured temperature is the average temperature in the dielectric layer within the range of the temperature sensing element

Characteristics of Assembling Thermistors

Adopting an assembled structure, with good component disassembly and easy maintenance;

Low cost of replacing vulnerable parts;

Complete specifications, stable and reliable performance.

insulation resistance

The insulation resistance at room temperature for assembling platinum thermistors should not be less than 100M Ω

The room temperature insulation resistance for assembling copper thermistors should not be less than 50M Ω. The test voltage for room temperature insulation resistance is 10-100V DC. Self heating effect: Platinum resistors allow a very large current of 5mA to pass through, resulting in a temperature rise of no more than 0.3 ℃. Thermal response time: When there is a step change in temperature, the time required for the output of the thermal resistor to change to 50% of the step change is called the thermal response time, represented by τ 0.5.

Thermal resistance time constant

The nominal pressure of a thermal resistor generally refers to the static external pressure that the protective tube can withstand at operating temperature without breaking.

The insertion depth of the thermistor is very small: it should not be less than 8-10 times the outer diameter of its protective sleeve.

Insulation resistance: When the ambient air temperature is 15-35 ℃ and the relative humidity is less than 80%, the insulation resistance is 20 megohms (voltage 100V)

The insulation resistance of the splash proof junction box should be 2 megohms (voltage 100V)

The resistance value (R0) of the thermistor temperature sensing element at 0 ℃ and its ratio to the resistance value (R100) at 100 ℃:

Ratio=R100/R

When the division marks are Pt10 and Pt100; R100 /R0 =1.3850±0.001

When the division marks are Cu50 and Cu100; R100 /R0 =1.3850±0.002