Measurement principle and range of armored thermocouple

Principles of Temperature Measurement

A thermocouple is a type of temperature sensing element that measures temperature by measuring potential through the process of welding two conductors with different compositions together. When there is a temperature difference between the two ends, a thermoelectric potential will be generated in the circuit. It is a modifier that can change the temperature signal to an electrical signal and then be displayed by a performance instrument.

The fundamental principle of measuring temperature with a thermocouple is the thermoelectric effect, which connects two metal conductors with different compositions into a closed loop. If the temperature of the two contacts is not equal, a thermoelectric potential will occur in the loop, forming a thermoelectric current. This is the thermoelectric effect.

A thermocouple is made by welding two different metal materials at one end. The welded end is called the measuring end, and the unwelded end is called the reference end. The reference end remains constant at a certain temperature (such as 00C) during application. When heating the measuring end, a thermoelectric potential occurs at the junction.

If the reference temperature is constant, the magnitude and bias of its thermoelectric potential are only related to the characteristics of the two metal materials and the measurement of the true temperature, and are related to the delicacy and correctness of the potential couple.

When measuring the true temperature change, the potential electric potential also changes accordingly, and there is a strong functional correlation between temperature and thermoelectric potential. By applying this correlation, temperature can be measured.

Temperature measurement category

Measure the temperature of the main steam in thermal power plants at temperatures above 500 ℃, the temperature of the superheated pipe wall, and the temperature of the low-temperature flue gas. Features: capable of measuring low temperatures, stable and reliable in function, simple in structure, easy to protect, and convenient for remote transmission and multi-point switching measurement of signals.

Temperature measurement range for different models: Important models: Scale mark: S or LB-3, with a lower limit of 1300 ℃ (short-term 1600 ℃). B or LL-2 has a lower limit of 1600 ℃ (short-term 1800 ℃), K or EU-2 has a lower limit of 1200 ℃ (short-term 1300 ℃), T or CK has a lower limit of -200~350 ℃ (short-term 400 ℃), E or EA-2 has a lower limit of -200~900 ℃. Thermal resistance: high measurement accuracy, stable function, high sensitivity, wide range of applications, can be tested at long intervals, and achieve active temperature control and recording.