熱電偶測溫分類

熱電偶感測器 (鎧裝熱電阻, 隔爆型鉑電阻, 高溫貴金屬 (鉑銠) 熱電偶, 防腐熱阻, End face thermal resistance, Power station thermocouple sensors, Hot runner thermocouple) is a kind of temperature sensing element. thermocouple directly measures temperature. Two different components of a conductor material composed of a closed loop. Due to different materials, different electron densities produce electron diffusion, and an electric potential is generated after stable equilibrium. When there is a gradient temperature at both ends, a current will be generated in the loop, generating thermoelectromotive force. The greater the temperature difference, the greater the current. The temperature value can be known after measuring the thermoelectromotive force. A thermocouple sensors is actually an energy converter that converts heat energy into electrical energy.

The technical advantages of thermocouples sensors: the thermocouple has a wide temperature measurement range, and its performance is relatively stable. The measurement accuracy is high, the thermocouple is in direct contact with the measured object, and is not affected by the intermediate medium. The thermal response time is fast, and the thermocouple responds flexibly to temperature changes. The measuring range is large, and the thermocouple can measure the temperature continuously from -40~+1600℃. The thermocouple has reliable performance and good mechanical strength. Long service life and convenient installation.

The galvanic couple must be composed of two conductor (or semiconductor) materials with different properties but meet certain requirements to form a loop. There must be a temperature difference between the measuring terminal and the reference terminal of the thermocouple.

The conductors or semiconductors A and B of two different materials are welded together to form a closed loop. 當兩個附著點之間存在溫差時 1 和 2 of the conductors A and B, 兩者之間產生電動勢, so a current of a magnitude is formed in the loop. 這種現象稱為熱電效應. Thermocouple is the application of this effect to work.

The thermocouple is actually a kind of energy converter. It converts thermal energy into electrical energy, and uses the generated thermoelectric potential to measure temperature. For the thermoelectric potential of a thermocouple, the following issues should be paid attention to :
1. The thermoelectric potential of a thermocouple is the difference between the temperature functions of the two ends of the thermocouple, not the temperature difference between the cold and working ends of the thermocouple.
2. The size of the thermoelectric potential generated by the thermocouple. When the material of the thermocouple is uniform, it has nothing to do with the length and diameter of the thermocouple, 但僅與熱電偶材料的成分和兩端的溫差有關.
3. After the material composition of the two thermocouple wires of the thermocouple is determined, the thermoelectric potential of the thermocouple is only related to the temperature difference of the thermocouple. If the temperature of the cold junction of the thermocouple remains constant, the thermoelectric potential of the thermocouple is only a single value function of the temperature of the working junction. Solder two conductors or semiconductors A and B of different materials to form a closed loop, 如圖所示. 當兩個附著點之間存在溫差時 1 和 2 of the conductors A and B, 兩者之間產生電動勢, thus forming an order of magnitude current in the loop. Thermocouples use this effect to work.