Platinum rhodium thermocouple and the working principle of bimetallic thermometer

Platinum rhodium thermocouple and the working principle of the bimetallic thermometer platinum-rhodium thermocouple made of power by thermoelectric effect, bimetallic thermometer is the use of different metal expansion rate, bimetallic thermometer through the metal of the principle of heat bilges cold shrink to two different expansion coefficient of metal iron and copper on a together, when the temperature rises bimetallic strip tends to bend, then can produce readings, bimetallic thermometer selection of sheath maerial is measuring the length of the measuring element extension. Thrust rod is refers to the connection at the bottom of the thread or the flange to the sheath maerial length, also called insertion depth. Sheath maerial of related technical parameters: 1, the sheath maerial diameter ( The thickness) 2, insert depth ( Length) 3, platinum rhodium thermocouple sheath maerial of material of electrode is composed of two different conductor material. When measuring the temperature difference is with the reference, the can produce thermoelectric power, the instrument will show thermoelectric potential corresponding temperature value. Thermal resistance is to use the resistance and temperature had a certain function of relationship theory. When the measured medium temperature change, its resistance value also along with the change, the instrument will show resistance corresponding temperature value. 3, the main technical parameters of the product standards: IEC1515IEC584IEC751JB/T5518 - 91 jb / T5582 - 91