The difference between thermocouple and thermal resistor, the difference between pt100 and cu50

Thermocouples are one of the most commonly used temperature detection elements in industry. The working principle of thermocouples is based on the Seebeck effect, that is, the two ends of two conductors of different components are connected into a loop. If the temperatures of the two connecting ends are different, a physical phenomenon of thermal current is generated in the loop.
Advantages are:
① High measurement accuracy. Because the thermocouple is in direct contact with the object to be measured, it is not affected by the intermediate medium.
② Wide measurement range. Commonly used thermocouples can be continuously measured from -50~+1600℃. Some special thermocouples can measure as low as -269℃ (such as gold, iron, nickel and chromium) and as high as +2800℃ (such as tungsten-rhenium).
③ Simple structure and easy to use. Thermocouples are usually composed of two different metal wires, and are not limited by size and opening. There is a protective sleeve outside, which is very convenient to use.
Thermal resistors
Thermal resistors are the most commonly used temperature detectors in medium and low temperature zones. Its main features are high measurement accuracy and stable performance. Among them, platinum thermal resistors have the highest measurement accuracy. They are not only widely used in industrial temperature measurement, but also made into standard reference instruments. 1. Thermocouple temperature measurement principle and materials
Thermocouple temperature measurement is based on the characteristic that the resistance value of metal conductors increases with the increase of temperature to measure temperature. Most thermal resistors are made of pure metal materials. Currently, platinum and copper are the most widely used. In addition, materials such as nickel, manganese and rhodium have begun to be used to manufacture thermal resistors.
2. Types of thermal resistors
1) Ordinary thermal resistors
From the temperature measurement principle of thermal resistors, it can be seen that the change of the measured temperature is directly measured by the change of the resistance value of the thermal resistor. Therefore, the change of the resistance of various wires such as the lead wire of the thermal resistor body will affect the temperature measurement.
2) Armored thermal resistors
The armored thermal resistor is a solid body composed of a temperature sensing element (resistor body), lead wire, insulating material, and stainless steel casing. Its outer diameter is generally φ2-φ8mm, and the minimum can reach φ0.25mm. Compared with ordinary thermal resistors, it has the following advantages: ① Small size, no air gap inside, thermal inertia, small measured value ② Good mechanical properties, vibration resistance, impact resistance; ③ Can be bent, easy to install ④ Long service life.
3) End face thermal resistor
The end face thermal resistor temperature sensing element is wound with specially treated resistance wire and is close 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 the end face temperature of bearings and other parts.
4) Flameproof thermal resistor
The flameproof thermal resistor uses a special structure of the junction box to confine the explosion of the explosive mixed gas inside its shell due to sparks or arcs to the junction box, and the production site will not cause an explosion. Flameproof thermal resistors can be used for temperature measurement in explosion-hazardous places in Bla--B3c level areas.
Pt100: used for thermal resistors, thermocouples, series temperature instruments, temperature transmitters, pressure differential pressure transmitters, hot runner heaters, compensation cables, control cables, etc.
Cu50: used for RTD, RTD thermometer, RTD calibrator, RTD simulator - copper RTD simulator, copper RTD, armored RTD, etc.
PT100 and CU50 measure different temperatures. PT100 measures high temperature, while CU50 measures low temperature.