Thermocouple temperature measuring thermocouple temperature measurement principle and the material is based on the metal conductor resistance value increases with the increase of the temperature of the properties for temperature measurement. Thermocouples are mostly made of pure metal materials, the application is a lot of platinum and copper, in addition, now began to use the materials such as nickel, manganese and rhodium thermocouple. Thermocouple is one of the industry commonly used temperature detecting element. The working principle of the thermocouple is based on baker ( seeback) Effect, that is, two different components of conductor ends connected into a circuit, such as two different connection end temperature, then to produce the physical phenomenon of thermal current in the circuit. Its advantage is high accuracy of measurement. Because of thermocouple direct contact with the object being measured, not affected by intermediate medium. (2) the measurement range. The commonly used thermocouple from - 50 ~ + 1600 ℃ can renew edge measurement, some special thermocouple low measurable to - 269℃( Such as gold iron nickel chrome) High, up to + 2800 ℃ ( Such as tungsten - Rhenium) 。 3. Simple structure, easy to use. Thermocouple is usually composed of two different kinds of metal wire, but is not limited by the size and the beginning of, outside has protective casing, which are very convenient. Thermocouple type and structure formation ( 1) Thermocouple types commonly used thermocouple could be divided into two types: standard thermocouple and non-standard thermocouple. Using standard thermocouple refers to the standard specifies the thermoelectric potential and the relationship between temperature, permissible error, and a unified standard score table of thermocouple, it has with matching display instrument to choose from. Non-standard thermocouple or on the order of magnitude less than the range using standardized thermocouple, generally no unified indexing table, mainly used for the measurement of some special occasions. Standardized thermocouple since January 1, 1988 in our country, the thermocouple and thermocouple were manufactured according to iec international standard, and specify the s, b, e, k, r, j, t seven standardization thermocouple type thermocouple for our country unified design. Pt100 temperature thermocouple is commonly used in low temperature zone of a detector. Its main characteristic is high accuracy, stable performance. The platinum thermocouple measuring accuracy is high, it is not only widely used in industrial temperature measurement, and is made into standard benchmark instrument. Thermocouple type 1) Ordinary thermocouples from the thermocouple temperature measurement principle, the measured the change in temperature is directly measured by thermocouple resistance change, therefore, the wires of a thermocouple body such as a variety of wire resistance change will affect temperature measurement. 2) Thermocouple is by thermal components ( The resistor body) , wire, insulation materials, stainless steel casing combination solid body, its diameter is commonly phi - 2 Phi is 8 mm, achieve more xiaoke phi is 0. 25mm。 Compared with conventional type thermocouple, it has the following advantages: (1) small volume, no internal air gap, thermal inertia, the measured value after small; (2) good mechanical properties, resistance to vibration and shock. (3) can bend, easy to install (4) long service life. 3) Capillary thermocouple ends thermocouple temperature sensing element resistance wire winding by special processing, close to the face in the thermometer. Compared with general axial thermocouple, it can reflect more correctly and quickly end face of the actual temperature being measured, is suitable for measuring temperature bearing and other parts of the face. 4) Flameproof thermocouple junction box flameproof thermocouple with special structure, its shell internal explosive mixed gas by affected by sparks or electric arc explosion limit within the junction box, that wouldn't make production field explosion. Flameproof thermocouple can be used in the bla B3c level zone with explosion danger place temperature measurement. Pt100: used for thermocouple, thermocouple, temperature meter, temperature transmitter, pressure differential pressure transmitter, hot runner heater, compensation cable, control cable, etc. Cu50: used for thermocouple, thermocouple thermometer, thermocouple checking instrument, thermocouple simulator - Thermocouple simulators, copper thermocouple, thermocouple, etc. Pt100 and cu50 measuring temperature is different, pt100 measurement of high temperature, cu50 measuring the temperature of the low.