1.Most common thermal resistance materials are single metal, and the widely used thermal resistance materials are platinum and copper. The graduation numbers of the thermal resistance are Cu50, Pt100, Pt1000, etc. The letter in front refers to the material of the thermal resistance, and the number behind is the resistance value of the thermal resistance. Thermocouples are made of two conductors of different compositions (called thermocouple wires or hot electrodes) connected at both ends into a loop. Common K-type thermocouples are composed of nickel-chromium-nickel-silicon.
2.Temperature measurement range
Thermal resistance is a common temperature sensor in medium and low temperature areas. It is divided into platinum thermal resistance, copper thermal resistance, etc., and the temperature measurement range is also different. Generally speaking, thermal resistance can measure the temperature from -200 to 600 ℃.Thermocouples have a large temperature measurement range and can measure temperatures from 0 to 1800°C. Ordinary K-type thermocouples can also measure temperatures from -40 to 1200°C.
3.Connection method
At present, there are three main connection methods of thermal resistance: two-wire, three-wire and four-wire. The accuracy of the two-wire is relatively low, while the four-wire system is more used for precise measurements in the laboratory. We usually use three-wire. Thermocouples are generally two-wire connection, which are different from the resistance output of the thermal resistance, and the output of the thermocouple is a mV signal.
