Analyses the characteristics and the structure principles of the bimetallic thermometer - Shanghai dragon instrument electric appliance co. , LTD

Bimetallic thermometer the advantage of fast response speed, small volume, good linearity and relatively stable, some products abroad also has high temperature performance. Bimetallic thermometer thermoelectric potential size only to the thermoelectric properties of thermal electrode material and temperature difference on both ends. Use the same kind of homogeneous conductor or semiconductor circuits, won't produce thermoelectric potential. Two thermocouple junction temperature T, T0, if T = T0, the thermocouple thermoelectric potential is zero. Law of intermediate temperature thermocouple indexing table laid the foundation for the development. For many years, scientists are trying to research what can use function equation to express thermocouple in piecewise function of the hot side ( Measurement end) Temperature and the relationship between the thermocouple loop of thermoelectric potential, failed to succeed. If two conductor A and B, respectively, with A third conductor of thermoelectric has A wide temperature range, long-term use of physical and chemical performance is stable. High electrical conductivity, small temperature coefficient of resistance; Does the configuration of the thermoelectric potential high flexibility, a linear between thermoelectric potential and temperature, easy to copy, simple process, cheap price. But the wrong with nickel and chromium - Nickel silicon bridge of compensation, its compensation bridge equilibrium 0? C。 When the cold end temperature of 30? Temperature of 900 C, thermometer instructions? C, is the practice of the furnace temperature is a few? To use standard electrode's law to definite element with temperature changes. Common bimetallic thermometer used in low temperature, thermocouple used in high temperature. If temperature beyond 500 degrees so bimetallic thermometer resistance will be very big, may affect the measurement result, that will not come out the status of the measurement results. Bimetallic thermometer to two different linear expansion coefficient of metal together, one end fixed, when the temperature changes, the two different kinds of metal thermal expansion, drive the pointer to indicate the temperature, that is the bimetallic thermometer.