Corrosion resistant and acid alkali resistant thermocoupleIt is a circuit composed of two conductors with different compositions connected at both ends. When the temperatures of the two junction points are different, an electromotive force is generated in the circuit, which is called thermoelectric effect, and this electromotive force is called thermoelectric potential. Thermocouples use this principle for temperature measurement, where the end directly used to measure the temperature of the medium is called the working end and the other end is called the cold end; Connect the cold end to the display instrument or matching instrument, and the display instrument will indicate the thermoelectric potential generated by the thermocouple.
Corrosion resistant and acid alkali resistant thermocoupleBasic knowledge
1. Thermoelectric effect: When two different conductors are connected together and the temperatures at both ends of the conductors are not the same, current is generated in the circuit formed by the conductors. This phenomenon is called the thermoelectric effect of matter (Seebeck effect). Thermoelectric properties are a common physical characteristic of matter.
2. Thermocouple: A pair of metal conductors used to measure temperature by measuring thermoelectric potential. Note that they are two different homogeneous conductors, and only a pair of metal conductors with good linearity, stability, high thermoelectric potential, and good corrosion resistance in the thermoelectric characteristic curve can be used for thermocouples.
3. Thermoelectric electrode: The two metal conductors that make up a thermocouple are called hot electrodes, one of which is called the positive electrode and the other is called the negative electrode.
4. Measurement end and reference end: The welding end of the thermocouple is called the measurement end, also known as the hot end, and the other end used to connect the display instrument is called the reference end, also known as the cold end.
5. Thermoelectric potential: The electromotive force generated in a circuit due to the temperature difference between the measuring end and the reference end is called thermoelectric potential, which includes two parts: thermoelectric potential and contact potential. When the temperature at the reference end is constant, the magnitude of the thermoelectric potential of the thermocouple corresponds one-to-one with the temperature at the measuring end.
6. Thermoelectric potential rate: refers to the change in thermoelectric potential of a thermocouple caused by a temperature change of 1 ℃, also known as the "Seebeck coefficient", measured in μ V/℃. Temperature needs to be converted into thermoelectric potential for calculation.
7. Basic laws: law of homogeneous conductor, law of intermediate conductor, law of intermediate temperature, law of connected conductor, law of reference electrode.
8. Origin: Based on the thermoelectric effect discovered by Seebeck in 1821, Becquerel first measured temperature based on the thermoelectric effect in 1826.
9. Scale mark: a naming symbol for a category of thermocouples with consistent thermoelectric characteristics within a certain range. Two thermocouples with the same thermoelectric electrode chemical composition have the same division mark.