A thermocouple is a temperaturemeasuring device consisting of two dissimilar conductors that contact each other at one or more spots. It
produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
Thermocouples are a widely used type of temperature sensorfor measurement and control,and can also convert a temperature gradient
into electricity. Commercial thermocouples are inexpensive,interchangeable, are supplied with standard connectors, and can measure a
wide range of temperatures. In contrast to most other methods of temperature measurement, thermocouples are self powered and require
no external form of excitation.
Thermocouples are widely used in science and industry; applications include temperature measurement for kilns, gas turbine exhaust,
diesel engines, and other industrial processes. Thermocouples are also used in homes, offices and businesses as the temperature
sensors in thermostats, and also as flame sensors in safety devices for gas-powered major appliances.