Thermocouples are the classification _ instrument

The classification of the thermocouple as follows the bop thermocouple waterproof thermocouple round plug type thermocouple flat plug type thermocouple compensation wire thermocouple thermal resistance is how to choose the thermocouple options: according to the scope of the measuring temperature above 500 ℃ generally choose thermocouple, usually selected thermocouple below 500 ℃; According to the accuracy of measurement choice: thermocouple with high accuracy requirement choice, to choose thermocouple accuracy is not high; According to the measurement range selection: measured by thermocouple temperature generally refers to the 'point', generally refers to the space average temperature measured by thermocouple; 2 wire thermocouple wiring simple, but to bring in additional error lead resistance. So shall not apply to the manufacturing accuracy of grade A thermocouple, and when use and lead wires have shoulds not be too long. Wire system can eliminate the influence of the lead resistance, measurement accuracy is higher than 2 wire system. As the process of detecting element, its wide application. Wire system not only can eliminate the influence of the lead resistance, and the connection wire resistance phase at the same time, also can eliminate the influence of the resistance. When in high precision measurement, must use the four wire system. Ordinary thermocouples from the thermocouple temperature measurement principle, the measured the change in temperature is directly measured by thermocouple resistance changes, it can directly measure or control - all kinds of production process 200℃- 600 ℃ range of liquid, steam and gas medium, as well as the temperature of the solid surface. As a result, the wires of a thermocouple body such as a variety of wire resistance change will affect temperature measurement. Usually and display meter, recording meter, electronic computer and other systems. Compression spring type thermal components, good seismic performance measurement range large imported film resistance element, reliable and steady performance. Thermocouple in the ambient temperature for 15 - 35 ° C, relative humidity is not more than 80%, the test voltage for 10 - 100V（ Dc) Electrode and the outer casing of the insulation resistance between > 100 m Ω. Thermocouples can be used to measure - 200 - 600 ℃ temperature range, can be connected directly with copper wires and secondary instrument use, due to the thermocouple has good electrical output characteristic, can be adjusted to display instrument, recorder, instrument, scanner, data recorder and computer provide accurate temperature signal. 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( Thermocouple smaller diameter, K type for phi is 0. 25 mm, E of phi 1. 0mm) 。 Thermocouple compared with the 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.