Thermocouple and double thermocouple what is the difference between the two temperature gauges _ instrument

Double t thermocouple products adopt water proof junction box, suitable for petrochemical environmental requirements, standards in accordance with JB/T5219 - fixed screw thread And JB/T5583-91 91 the provisions of the thermocouple; Fixed flange in addition to the above standard at the same time, increase the three different welding method, the different forms of sealing surface mounting flange installation disk, choose and meet the needs of different users. Type B fixed flange, is flat welding steel flange ( JB81 - 59) Equivalent chemical standard ( HG5010 - 58岁的HG5019 - 58) Use smooth seal face, nominal Pg = 25 KGF/cm2 suitable for general requirements. C type fixed flange, and weld steel flat flanges ( JB81 - 59) Equivalent chemical standard ( HG5010 - 58岁的HG5019 - 58) Using concave-convex sealing surface, nominal pressure Pg = 25 KGF/cm2 suitable for harmful toxic medium, strong anti leakage leakproof performance type D fixed flange, butt welding steel flange ( JB82 - 59) Equivalent chemical standard ( HG5016- 58) The concave and convex seal face, nominal pressure Pg = 100 KGF/cm2 has good sealing, suitable for sealing and pressure has certain requirements of the occasion. 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. Thermocouple is by thermal components ( The resistor body) , wire, insulation materials, stainless steel casing combination solid body, its diameter is generally from 2 to 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, small measuring hysteresis; (2) good mechanical properties, resistance to vibration and shock. (3) can bend, easy to install (4) long service life. Thermocouple temperature measuring instrument is commonly used in temperature measuring element, is made up of two different components of the conductor when two ends synthesis loop, when the two junction thermocouple temperature is not at the same time, will produce thermal current in the circuit. If the work end of the thermocouple with the reference entity temperature difference, display instrument will indicate the thermocouple thermoelectric potential of the corresponding temperature value. Thermocouple is a kind of temperature sensor, it is smaller than the diameter of a prefabricated thermocouple, flexible, good vibration resistance, suitable for installation in the case of prefabricated thermocouple can't install, the company produces the thermocouple used to introduce thermocouple temperature measuring element, therefore, is accurate, sensitive, fast thermal response time, stable quality, long service life, etc.