Introduktion af termoelement og temperaturmålingsprincip

1. Introduktion til termoelementer

Thermoelectric temperature recorders often use thermocouples as temperature measuring elements. It is widely used to measure temperatures in the range of -200℃~1300℃. In special cases, it can measure high temperatures of 2800℃or low temperatures of 4K. It has the characteristics of simple structure, low price, high accuracy, and wide Temperaturmålingsområde . Da termoelementer omdanner temperatur til elektrisk mængde til påvisning, er det meget praktisk at måle og kontrollere temperaturen såvel som at amplificere og omdanne temperatursignaler, og er egnet til langdistancemåling og automatisk kontrol . i kontakttemperaturmålingsmetoder, termoelectric termometer anvendes bredt .} i kontaktstemperaturmålingsmetoder, termoelektriske termometer bruges {.}}}} i kontakttemperatur

2. termoelement temperaturmålingsprincip:

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}}, there is also a temperature difference potential in conductors A and B. Therefore, the total thermoelectric potential EAB (T, T0) of the closed loop should be the algebraic sum of the contact potential and the temperature difference potential, that is: 4. Total thermoelectric potential of the closed loop For Det valgte termoelement, når referencetemperaturen er konstant, bliver det samlede termoelektriske potentiale en enkeltvurderet funktion af temperaturen t ved måleenden, dvs. EAB (ｔ, t0)=f (t) . Dette er det grundlæggende princip for termokobel temperaturmåling .} i faktisk temperaturmåling, tilslutning, tilslutning af truften og instrumenter og instrumenter og instrumenter og instrumenter skal være ved at være ledning introduceret i den lukkede sløjfe af termoelementet .