Thermopile is a kind of infrared thermopile sensor, which is composed of thermocouple. It is composed of two or more thermocouples in series, and the thermoelectric potential output by each thermocouple is superimposed on each other.
The absorption film irradiated by infrared ray is a kind of film with small heat capacity and easy to rise temperature. The lower part close to the center of the lining plate is a hollow structure, which ensures the temperature difference between the cold end and the temperature measuring end. The thermocouple consists of polysilicon and aluminum, which are connected in series. When the temperature of each thermocouple rises, the thermoelectric EMF VN will be generated between the thermocouples, so the sum of their voltages can be obtained at the output end.
The radiation receiving surface is divided into several blocks, each of which is connected with a thermocouple and connected in series to form a thermopile. According to different applications, the practical thermopile can be made into thin wire type and thin film type, as well as multi-channel type and array type devices.
Characteristic of the infrared thermopile sensor:
1. The infrared thermopile sensor directly induces thermal radiation, providing a perfect solution for non-contact temperature measurement. Its innovative silicon-based micromachining technology ensures its excellent long-term stability, very low temperature sensitivity, and coefficient and excellent photoelectric characteristics.
2. The infrared thermopile sensor makes the non-contact temperature measurement system have a very low price.
3. It does not need to be cooled, but it can reach the accuracy of ± 1℃ in the whole temperature measurement range.
4. For a relatively narrow temperature measurement range, such as body temperature measurement, the accuracy can reach ± 0.1℃.
As a temperature detection device, it has been put into widespread use, mainly applied in ear thermometer, radiation thermometer, electric oven, food temperature detection and other fields.