Introduction to the structural characteristics and working principles of thermal resistors!

1. Structural features of thermal resistors:
Thermal resistors are usually used in conjunction with display instruments, recording instruments and electronic regulators. They can directly measure the temperature of liquid, steam and gas media and solid surfaces in the range of -200℃ to +600℃ in various production processes.
(1) WZ series assembled thermal resistors: usually composed of temperature sensing elements, mounting fixtures and junction boxes, with the advantages of high measurement accuracy, stable and reliable performance. In actual application, Pt100 platinum thermal resistors are the most widely used.
(2) WZPK series armored platinum thermal resistors: armored thermal resistors are a solid body composed of temperature sensing elements, leads, insulating materials and stainless steel casings. They have the following advantages: slender body, fast thermal response time, vibration resistance, long service life, etc.
(3) Flameproof thermal resistor: Flameproof thermal resistor uses a specially structured junction box to confine the explosion of explosive mixed gas inside the junction box due to sparks or arcs, so that the explosion will not occur at the production site.
(4) End face thermal resistor: The end face thermal resistor temperature sensing element is made of specially treated resistance wire and is tightly attached to the end face of the thermometer. Compared with general axial thermal resistors, it can more accurately and quickly reflect the actual temperature of the measured end face and is suitable for measuring surface temperature.
2. Working principle of thermal resistor: Thermal resistor is a commonly used temperature measuring element in medium and low temperature areas. Thermal resistors measure temperature by using the property that the resistance of a material changes with temperature. The heated part (temperature sensing element) of the thermal resistor is evenly wound on a skeleton made of insulating material with fine metal wire. When there is a temperature gradient in the measured medium, the measured temperature is the average temperature of the medium layer within the range of the temperature sensing element. Its main features are high measurement accuracy and stable performance. Among them, platinum thermal resistors have the highest measurement accuracy.