Einführung des Thermoelement- und Temperaturmessungsprinzips

1. Einführung in Thermoelemente

Thermoelektrische Temperaturrekorder verwenden häufig Thermoelemente als Temperaturmesselemente . Es wird häufig verwendet, um die Temperaturen im Bereich von -200 Grad ~ 1300 Grad . In besonderen Fällen zu messen, kann hohe Temperaturen von 2800 Grad messen. wide temperature measurement range. Since thermocouples convert temperature into electrical quantity for detection, it is very convenient to measure and control temperature, as well as to amplify and transform temperature signals, and is suitable for long-distance measurement and automatic control. In contact temperature measurement methods, thermoelectric thermometers are widely used.

2. Thermoelement -Temperaturmessungsprinzip:

Definition: A sensor composed of two conductors that converts temperature into thermoelectric potential is called a thermocouple. 2. Temperature measurement principle: The temperature measurement principle of thermocouples is based on the thermoelectric effect. Connect conductors A and B of two different materials in series to form a closed loop. When the temperatures of the two junctions 1 and 2 are different, if T>T0 (as shown in Figure 12-1 Thermoelectric effect), a thermoelectric potential will be generated in the loop, and a certain amount of current will be generated in the loop. This phenomenon is called the thermoelectric effect. The thermoelectric potential is recorded as EAB, and conductors A and B are called thermoelectrodes. Junction 1 is usually welded together. When measuring, it is placed in a temperature measurement location to feel the measured temperature, so it is called the measuring end (or working end, hot end). Junction 2 requires a constant temperature and is called the reference end (or cold end). 3. Thermoelectric effect: The closed circuit of the thermocouple composed of conductors A and B has two contact potentials, eAB (T) and eAB (T0), at the two junctions. Because T>T {{0}}, es gibt auch ein Temperaturdifferenzpotential in den Leiter A und B .. Daher sollte der gesamte thermoelektrische Potential EAB (t, t 0) des geschlossenen Loops das geschlossene Temperaturpotential und das Temperaturpotential des geschlossenen Temperaturpotentials sein. the selected thermocouple, when the reference temperature is constant, the total thermoelectric potential becomes a single-valued function of the temperature T at the measuring end, that is, EAB (Ｔ, T0)=f (T). This is the basic principle of thermocouple temperature measurement. In actual temperature measurement, connecting wires and instruments must be in die geschlossene Schleife des Thermoelements eingeführt .