Termopāra un temperatūras mērīšanas principa ieviešana

1. Ievads termopāros

Termoelektriskās temperatūras ierakstītāji bieži izmanto termopārus kā temperatūras mērīšanas elementus . To plaši izmanto temperatūras mērīšanai diapazonā no -200 grāda ~ 1300 grādu . īpašos gadījumos, jo augstas temperatūras var izmērīt augstas temperatūras. 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. termopāra temperatūras mērīšanas princips:

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}}, vadītājiem a un b {{0, ir arī temperatūras starpības potenciāls, kopējam termoelektriskajam potenciālam EAB (t, t 0) slēgtai cilpai jābūt ar apkopotu algebrisko summu un kopējo temperatūras potenciālu, kas ir paredzēts, un 4.}}}} kopējais termiskais potenciāls, kas ir paredzēts. termopārs, kad atsauces temperatūra ir nemainīga, kopējais termoelektriskais potenciāls kļūst par vienvērtīgu temperatūras t funkciju mērīšanā, tas ir, eab (ｔ, t0) =} f (t) . Tas ir pamatprincips, kas paredzēts termopāra temperatūras mērījumiem .}, kas ir paredzēts, lai noteiktu termopāra. termopārs .