Thermopile is a kind of thermoluminescence infrared sensor, which is a device composed of thermocouple. It has been widely used as a temperature detection device in ear thermometer, radiation thermometer, electric oven, food temperature detection and other fields. So, how does a thermopile sensor work? Let's answer this question.
As long as any object is above absolute zero, it will radiate energy at a certain wavelength, but the radiation energy at low temperature is very weak. At room temperature, all objects in nature are the emission source of infrared radiation, but the wavelength of infrared radiation is different.
The principle of thermopile temperature sensor is based on Seebeck effect: a closed circuit composed of two conductive materials with different work function. When the temperature at the two contact points is different, the carriers inside the material move towards the lower temperature end due to the decrease of temperature gradient, and the accumulated accumulation will be formed at the end of low temperature, then a thermoelectric potential will be generated in the loop. This structure is called thermocouple, the temperature of the object to be measured can be detected when the voltage change is separated from each other.
The thermopile sensor converts the infrared radiation absorbed into heat energy, and converts the temperature into electronic signal, which is amplified and displayed. As a non-contact infrared temperature sensor, thermopile can quickly measure the surface temperature of the object without directly contacting the measured object. It can measure the high temperature, dangerous or moving objects without polluting or damaging the measured object.
At present, it has been widely used in the field of forehead temperature gun, ear temperature gun, intelligent home appliances, lamp switch, food temperature detection and so on.