The Use Of Thermocouples Is Very Convenient


The application of thermocouple is very extensive, it has many advantages such as simple structure, convenient manufacture, wide measurement range, high precision, small inertia and easy transmission of output signal. In addition, because the thermocouple is a kind of active sensor, the measurement does not need to be applied to the power supply, the use is very convenient, Thermocouple so it is often used to measure the temperature of the gas or liquid in the furnace, the pipe and the surface temperature of the solid.

Thermocouples are commonly used in temperature measuring instruments, which directly measure temperature and convert the temperature signal into thermoelectric signal, through electrical instrumentation (two meters) to the temperature of the measured medium. The shape of various thermocouples is often different because of the need, but their basic structure is roughly the same, usually by the thermoelectric pole, Thermocouple insulation sleeve protection pipe and junction box, and other major components, usually and display instruments, record instruments and electronic regulator supporting the use.

① measurement accuracy is high. Because the thermocouple is directly contacted with the object being measured, it is not affected by intermediate medium.

② measurement range is wide. The commonly used thermocouples can be measured from -50~+1600℃, and some special thermocouples can be measured at least -269℃ (such as ferro-nickel chromium), up to +2800℃ (such as tungsten-rhenium).

③ structure is simple and easy to use. Thermocouples are usually made up of two different kinds of wire and are not limited by size and opening, but have a protective casing, Thermocouple which is very convenient to use.

Fundamentals of Thermocouple Thermometry

The conductors of two different materials or semiconductors A and B are welded together to form a closed loop. When there is a temperature difference between the two attachment points 1 and 2 of conductors A and B, an electromotive force is generated between the two, thus forming a current in the loop, a phenomenon called thermoelectric effect. Thermocouples Use this effect to work.

Thermocouple is a temperature element, is a meter, it directly measures the temperature, and the temperature signal into a thermoelectric signal, through the electrical instrument (two meters) into the medium of measurement. Thermocouple temperature measurement is the basic principle of two different components of the material conductor of the closed loop, when the temperature gradient at both ends, Thermocouple there will be current through the loop, at this point there is a electromotive force-thermoelectric dynamic, which is called the Peltier effect. The homogeneous conductor of two different compositions is thermoelectric, the one end of the higher temperature is the working end, the lower end of the temperature is the free end, and the free end is usually at a constant temperature. According to the function relation of thermoelectric dynamic potential and temperature, the thermocouple scale table is made. Thermocouple The scale table is the free end temperature at 0 ℃ conditions, the different thermocouple has different scale table.