Thermocouples are a common temperature measuring element in temperature measuring instruments. They directly measure temperature and convert temperature signals into thermoelectric potential signals, which are then converted into the temperature of the measured medium through electrical instruments (secondary instruments). The basic structure of thermocouples is roughly the same, usually consisting of thermocouples, insulating sleeve protection tubes, and junction boxes. They are usually used in conjunction with display instruments, recording instruments, and electronic regulators. The characteristics of thermocouples include wide range, high accuracy, simple operation, strong durability, and fast response speed. These characteristics make thermocouples widely used in the industrial field.
1. There are many types of thermocouples, and the most common ones are standard thermocouples and non-standard thermocouples. Among them, K-type thermocouples are base metal thermocouples with strong oxidation resistance. They can measure medium temperatures of 0 to 1300 ° C and are suitable for continuous use in oxidizing and inert gases. Use. However, K-type thermocouples are not suitable for bare wire use in vacuum, sulfur-containing, carbon-containing atmospheres, and redox alternating atmospheres. In addition, the advantages of thermocouples include high measurement accuracy, wide measurement range, simple structure, and easy use.
2. The working principle of thermocouples is based on the Seebeck effect, that is, when two conductors of different materials form a closed loop, when there is a temperature gradient at both ends, a current will pass through the loop, and at this time there will be an electromotive force between the two ends – the thermoelectric electromotive force. The magnitude of this electromotive force is related to the properties of the material itself and the temperature of the node, and can be expressed as a contact potential and a thermoelectric potential. The contact potential is the potential difference formed by the electron migration and diffusion at the node due to the different free electron densities of the two conductors; the thermoelectric potential is caused by the difference in free electron concentration formed by the different temperatures at both ends of the metal conductor.
Thermocouples are a common temperature measuring element in temperature measuring instruments. They directly measure temperature and convert temperature signals into thermoelectric potential signals, which are then converted into the temperature of the measured medium through electrical instruments (secondary instruments). The basic structure of thermocouples is roughly the same, usually consisting of thermocouples, insulating sleeve protection tubes, and junction boxes. They are usually used in conjunction with display instruments, recording instruments, and electronic regulators. The characteristics of thermocouples include wide range, high accuracy, simple operation, strong durability, and fast response speed. These characteristics make thermocouples widely used in the industrial field.
1. There are many types of thermocouples, and the most common ones are standard thermocouples and non-standard thermocouples. Among them, K-type thermocouples are base metal thermocouples with strong oxidation resistance. They can measure medium temperatures of 0 to 1300 ° C and are suitable for continuous use in oxidizing and inert gases. Use. However, K-type thermocouples are not suitable for bare wire use in vacuum, sulfur-containing, carbon-containing atmospheres, and redox alternating atmospheres. In addition, the advantages of thermocouples include high measurement accuracy, wide measurement range, simple structure, and easy use.
2. The working principle of thermocouples is based on the Seebeck effect, that is, when two conductors of different materials form a closed loop, when there is a temperature gradient at both ends, a current will pass through the loop, and at this time there will be an electromotive force between the two ends – the thermoelectric electromotive force. The magnitude of this electromotive force is related to the properties of the material itself and the temperature of the node, and can be expressed as a contact potential and a thermoelectric potential. The contact potential is the potential difference formed by the electron migration and diffusion at the node due to the different free electron densities of the two conductors; the thermoelectric potential is caused by the difference in free electron concentration formed by the different temperatures at both ends of the metal conductor.
