Bimetallic thermometer has the advantages of fast response, small size, good linearity, stability, and some foreign products have high temperature performance.

The thermoelectric potential of bimetallic thermometer is only related to the thermoelectric properties of thermoelectric material and the temperature difference between two ends.

Using the same kind of conductor or semiconductor to form a circuit, it will not produce thermal potential.

Thermocouple two contact temperature T, T0, if T=T0, thermocouple thermoelectric potential is zero. The intermediate temperature law lays the foundation for the development of the thermocouple indexing table.

For many years, scientists have tried to study the possibility of using function relationship even with piecewise function to express the heat end of thermocouple (measuring end) the relationship between thermoelectric temperature and thermocouple loop generated, ultimately did not succeed.

If the two conductor A, B, respectively, and the composition of the thermal conductivity of the third conductor has a wide range of temperature, long-term use of physical and chemical properties of stability

High conductivity, temperature coefficient of resistance is small; the configuration of the high sensitivity of the thermoelectric potential, between thermoelectric potential is linear with temperature, easy to copy, simple process, low price.

But the misuse of compensation bridge supporting nickel chromium nickel silicon, the balance compensation of the bridge 0º C. When the cold end temperature of 30º C, C, 900º thermometer indicates the temperature; the actual temperature of the heating furnace is? To determine the temperature components with standard electrode law.