Characteristics of bimetallic thermometers
The advantages of bimetallic thermometers are fast response speed, small size, good linearity, and relatively stable. Some foreign products also have high-temperature working performance.
The thermoelectric potential of a bimetallic thermometer is only related to the thermoelectric properties of the thermoelectric electrode material and the temperature difference between the two ends.
Using the same homogeneous conductor or semiconductor to form a circuit will not generate thermoelectric potential.
The temperature of the two contacts of the thermocouple is T, T0. If T=T0, the thermoelectric potential of the thermocouple is zero. The law of intermediate temperature lays the foundation for developing a thermocouple graduation table.
If two types of conductors A and B are combined with a third conductor to form thermoelectric devices, they have a wide temperature measurement range and stable physical and chemical properties for long-term use.
High conductivity, low resistance temperature coefficient; ※ The configured thermoelectric potential has high sensitivity, linear relationship between thermoelectric potential and temperature, easy to replicate, simple process, and low price.
But the matching nickel chromium nickel silicon compensation bridge was mistakenly used, and the balance point of the compensation bridge was 0º C。 When the cold end temperature is 30º C. The thermometer indicates a temperature of 900º C. What is the actual temperature of the heating furnace? Determine the components that vary with temperature using the standard electrode law.
Generally, bimetallic thermometers are used at low temperatures, while thermocouples are used at high temperatures. If the temperature exceeds 500 degrees, the resistance value of the bimetallic thermometer will be very high, which may affect the measurement results, and even lead to situations where the measurement results cannot be obtained
