Measuring range and temperature measuring principle of thermocouple is what _ instrument

Thermocouple as the temperature measurement sensor, usually with temperature transmitter, controller and display instrument, such as process control system, to directly measure or control in the production of a variety of 0 Fluid over a range of 1800 ℃, steam and gas medium and solid surface temperature. Temperature measuring principle of thermocouple is to use two different ingredients of conductor welded together, two end temperature is not at the same time, there will be a thermoelectric potential generated in the circuit, thus the potential galvanic couple is determined by measuring the electric potential to measure the temperature of a thermal original, it is a kind of converter, it can make temperature signals into electrical signals and then displayed by the display instrument. Thermocouple measuring temperature is the basic principle of thermoelectric effect, will be connected to the metal conductor fore and aft of the two different ingredients into a closed loop, such as the temperature of the two contact, can produce thermoelectric emf in the loop, form the thermal current, this is called the thermoelectric effect. Thermocouple is one end will be two different kinds of metal material welding, welding, called at the end of the measuring end not welding is called a reference at the end of the end, the reference side when use constant in a certain temperature (usually Such as 00 c) When to measure the heating, thermoelectric potential is at the junction produced. Such as reference end temperature constant, the size and direction of thermoelectric potential only with the characteristics of two kinds of metal material and measure the temperature, and has nothing to do with potential galvanic fine and length. When measuring the temperature change, the potential potential changes, and the temperature and a fixed function relationship between thermoelectric potential, take advantage of this relationship can measure the temperature. Measuring range of commonly used instrument have thermocouple temperature. Thermocouple: measuring high temperature above 500 ℃, power of main steam temperature, superheated tube wall temperature, high temperature flue gas temperature. Features: to measure the high temperature, stable performance, accurate and reliable, simple structure, easy to maintain, facilitate remote transmission and multicast switching signal measurement. The main models: dividing number: S or LB - Upper limit of 3 1300 ℃ ( A short 1600 ℃) 。 B or LL - Upper limit of 2 1600 ℃ ( A short 1800 ℃) K or the EU Upper limit of 2 1200 ℃ ( A short 1300 ℃) T or ceiling - CK 200～350℃( A short 400 ℃) E or EA - Upper limit of 2 - 200 ~ 900 ℃ thermocouple: high measuring accuracy, stable performance, high sensitivity, wide application range, which can be answers at, realizing automatic temperature control and recording. Platinum thermocouple, high temperature 650 ℃, Pt50, Pt100, copper resistance: 50 - 150℃Cu50,Cu100。 Note: since the error due to thermal effect, Pt work for less than 6 d current ma, the effects of hysteresis, heat capacity, good heat exchange, measurement is accurate. Installation: installed, and the formation of measured medium counter-current, into at least 90 ° degree no. : S or LB - Upper limit of 3 1300 ℃ ( A short 1600 ℃) 。 B or LL - Upper limit of 2 1600 ℃ ( A short 1800 ℃) K or the EU Upper limit of 2 1200 ℃ ( A short 1300 ℃) T or ceiling - CK 200～350℃( A short 400 ℃) E or EA - Upper limit of 2 - 200 ~ 900 ℃, high measuring accuracy, stable performance, high sensitivity, wide application range, which can be answers at, realizing automatic temperature control and recording.