Thermocouple

1. How it works

Based on the Seebeck effect, two conductors or semiconductors of different materials form a closed loop, and when there is a temperature difference between the two ends, the thermoelectric motive force is generated in the loop, and the temperature is calculated by measuring the thermoelectric motive force.

2. Structure composition

It is generally composed of a thermal electrode, an insulating sleeve, a protective tube and a junction box. The thermal electrode is used to sense the temperature and generate the thermoelectric potential, the insulating sleeve prevents the thermal electrode from short-circuiting, the protective tube protects the internal components from the external environment, and the junction box is used to connect the measurement circuit.

3. Main types

Common types include K type, J type, T type, E type, etc. Such as K type thermocouple, wide range of temperature measurement, high precision, good stability and cost-effective, widely used.

4. Application field

Widely used in industrial production temperature monitoring and control, such as steel, chemical, electric power and other industries; It is also used for accurate temperature measurement in scientific research experiments, and temperature control of household appliances in daily life.

Thermocouple Types：

Type K (nickel-chromium-nickel-silicon) : good linearity, high sensitivity, stable oxidation resistance, temperature measurement -200 ℃ to 1300℃, widely used in petroleum, chemical and other industries.

Type E (Nichme-Cu-Ni) : the highest thermoelectric motive force and sensitivity, humidity resistance, low temperature stability, temperature measurement -200 ℃ to 900℃, for refrigeration, environmental monitoring and other scenarios with high response and sensitivity requirements.

J type (Fe-Cop-nickel) : low price, good linearity, can work in oxidation and reduction atmosphere, temperature measurement -210 ℃ to 1200℃, used in chemical and metallurgical industries.

T-type (copper-copper-nickel) : -200℃ to 350℃, good stability and uniformity, approximately linear, high sensitivity, low price, suitable for low temperature and high precision measurement, such as laboratory low temperature experiments, biomedical fields.

Type S (platinum rhodium 10-platinum) : precious metal thermocouple, high precision, stable oxidation resistance, long-term use in oxidation, inert atmosphere, temperature measurement 0℃ to 1600℃, for high temperature and precision measurement, such as glass, ceramic industry and scientific research.

Type R (platinum-rhodium 13-platinum) : similar to type S, the thermoelectric electrodynamic force is slightly larger, high temperature stability and oxidation resistance, temperature measurement 0℃ to 1700℃, for high temperature measurement and calibration, in scientific research and high-end industrial applications.

Type B (platinum-rhodium 30-platinum-rhodium 6) : stable oxidation resistance at high temperatures, suitable for oxidation, inert atmosphere, temperature measurement 600℃ to 1800℃, often used in high temperature furnace, glass kiln temperature measurement.