What is a Thermocouple?

Thermocouple, also called thermal junction, thermoelectric thermometer, or thermel, is a sensor used to measure temperature. It consist of two wires of made from different metals joined at each end.One junction is placed where the temperature is to be measured, and the other is kept at a constant lower temperature. This junction is where the temperature is measured. A measuring instrument is connected in the circuit. When the temperature changes,the temperature difference causes the development of an electromotive force (known as the Seebeck effect,also known as the thermoelectric effect,) that is approximately proportional to the difference between the temperatures of the two junctions. Since different metals generate different voltages when exposed to a thermal gradient, the difference between the two measured voltages corresponds to temperature. Which is a physical phenomenon that takes the differences in temperature and converts them into differences in electrical voltages.So temperature can be read from standard tables, or the measuring instrument can be calibrated to read temperature directly.

Types and application areas of thermocouples：
There are many types of thermocouples, each with its own unique characteristics in terms of temperature range, durability, vibration resistance, chemical resistance, and application compatibility. Type J, K, T, & E are “Base Metal” thermocouples, the most common types of thermocouples.Type R, S, and B thermocouples are “Noble Metal” thermocouples, which are used in high temperature applications.
Thermocouples are used in many industrial, scientific, and so on. They can be found in nearly all industrial markets:Power Generation, Oil/Gas,Food processing equipment,Plating baths,Medical equipment,Industrial processing,Pipe tracing control,Industrial heat treating,Refrigeration temperature control,Oven temperature control,etc. Thermocouples are also used in everyday appliances like stoves,furnaces, oven,gas stove, gas water heater ,and toasters.
Actualy,people choose use thermocouples are typically selected because of their low cost, high temperature limits, wide temperature ranges, and durable nature. So thermocouples are one of the most widely used temperature sensors available.