The advantages of bimetal thermometers are fast response speed, small size, good linearity, and stability. Some foreign products also have high temperature performance.
The thermoelectric potential of the bimetal thermometer is only related to the thermoelectric properties of the thermoelectrode material and the temperature difference between the two ends.
Using the same homogeneous conductor or semiconductor to form a loop will not generate thermoelectric potential.
The two junction temperatures of the thermocouple are T and T0. If T=T0, the thermoelectric potential of the thermocouple is zero. The law of intermediate temperature lays the foundation for the formulation of thermocouple index tables.
For many years, scientists have tried to study whether a functional relationship or even a piecewise function can be used to express the relationship between the temperature of the hot end (measurement end) of the thermocouple and the thermoelectric potential generated by the thermocouple circuit, but ultimately failed.
If two kinds of conductors A and B respectively form a thermoelectric with the third conductor, they have a wide temperature measurement range, and the physical and chemical properties of long-term use are stable.
High conductivity, low temperature coefficient of resistance; ※The configured thermoelectric potential has high sensitivity, linearity between thermoelectric potential and temperature, easy to copy, simple process and low price.
However, the compensation bridge of nickel-chromium-nickel-silicon is wrongly used, and the balance point of the compensation bridge is 0ºC. When the cold junction temperature is 30º C and the thermometer indicates the temperature is 900º C, what is the actual temperature of the heating furnace? The standard electrode law can be used to determine the temperature-dependent components.
Generally bimetal thermometers are used at low temperatures, and thermocouples are used at high temperatures. If the temperature exceeds 500 degrees, the resistance value of the bimetal thermometer will be very large, which may affect the measurement results, and even the measurement results may not be available.
