The advantages of bimetal thermometers are fast response, small size, good linearity, and stability. Some foreign products also have high temperature performance.
The thermoelectric potential of a bimetal thermometer is only related to the thermoelectric properties of the hot electrode material and the temperature difference at both ends.
Using the same type of homogenous conductor or semi-conductor to form a loop, no thermoelectric potential is generated.
Thermocouple two junction temperature T, T0, if T = T0, the thermocouple thermoelectric potential is zero. The intermediate temperature law lays the foundation for the establishment of a thermocouple index table.
For many years, scientists have attempted to investigate whether the relationship between the thermocouple's hot-end (measurement) temperature and the thermocouple's thermoelectric potential can be expressed in a functional or even a piecewise function and ultimately fail to succeed.
If the two conductors A, B and the third conductor respectively have a wide temperature measurement range for thermoelectricity, the long-term use of the physical and chemical properties is stable.
High conductivity, low temperature coefficient of resistance; ※ High thermoelectric sensitivity of configuration, linearity between thermoelectric potential and temperature, easy to copy, simple process, and low price.
However, a nickel-chromium-nickel-silicon compensating bridge was wrongly used to compensate for the balance point of the bridge and 0 or C; When the temperature of the cold junction is 30º C, the temperature indicated by the temperature meter is 900º C, what is the actual temperature of the heating furnace? In order to use the standard electrode law to determine the components that change with temperature.
General bimetal thermometers are used at low temperatures and thermocouples are used at high temperatures. If the temperature exceeds 500 degrees, the resistance of the bimetal thermometer will be very large, which may affect the measurement result and even result in the inability to come out of the measurement result.