Thermal resistance principle and types of temperature measurement is introduced

Thermal resistance is low temperature zone in one of the most commonly used temperature detector. Its main characteristic is high accuracy, stable performance. Among them is platinum thermal resistance measurement accuracy is the highest, it is not only widely used in industrial temperature measurement, and is made into standard benchmark instrument.

1.

thermal resistance temperature measurement principle and material thermal resistance temperature measurement is based on the metal conductor resistance value increases with the increase of the temperature of the properties for temperature measurement. Heat resistance is mostly made of pure metal materials, the application at present most is platinum and copper, in addition, now have begun to use the materials such as nickel, manganese and rhodium manufacturing thermal resistance.

2, thermal resistance of type

1) ,

normal thermal resistance in temperature measuring principle of thermal resistance, measured the change in temperature is directly measured by the change of the thermal resistance tolerance, therefore, the thermal resistance of lead wire and other wire resistance change will affect temperature measurement.

2)

armoured, armored thermal resistance heat resistance 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, minimum of phi mm. Compared with the normal thermal resistance, 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.

3) ,

the end resistance transverse thermal resistance temperature sensing element resistance wire winding by special processing, close to the face in the thermometer. Compared with general axial thermal resistance, 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 thermal resistance flameproof thermal resistance through the special structure of the junction box, put the 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.