MEMS based thermopile infrared sensor technology helps prevent and control the epidemic
Scheme details
Programme background
Novel coronavirus infection is a very common disease in 2020. People from all walks of life pay homage to the heroes who are fighting on the front line and contribute to the Anti Japanese war in various ways.
The novel coronavirus infection in Xinxian County, Xinyang Province, is closely related to the situation in Henan Province, which is close to Hubei Wuhan. The epidemic prevention and control materials are seriously lacking in the county, and the pressure of prevention and control is doubled. In February 3rd, novel coronavirus Group donated $1 million yuan to the Xinxian County Red Cross Society in Xinyang, which is specially used to purchase new coronavirus pneumonia needed medical supplies in the region and meet some emergency cash needs in the region. It is a modest contribution to resolutely win the battle against epidemic prevention and control in Xinxian County.
In the process of novel coronavirus control, ventilator, monitor, oxygen generator, negative pressure ambulance and other medical products played a major role. These do not leave the support of sensor technology. Next, the author will focus on the principle of infrared thermopile sensor and its key application in this outbreak.
Product overview
As long as the temperature of any object in the universe is higher than absolute zero, it will radiate energy at a certain wavelength - that is, infrared radiation. Therefore, under the natural temperature, all objects are emission sources of infrared radiation, but the infrared wavelength of infrared radiation is different. For example, the human body temperature is 37 ?, the infrared radiation wavelength is 9-10 � m; the infrared radiation wavelength of 400-700 ? objects is 3-5 � M.
Infrared is also part of the solar spectrum, an invisible light. Like all electromagnetic waves, it has the properties of reflection, refraction, scattering, interference, absorption, etc. The propagation speed of infrared light in vacuum is 3 � 108m / s, which will cause attenuation in the medium, especially in the metal. But infrared radiation can pass through most semiconductors and some plastics, and most liquids absorb infrared radiation very much.
By using the characteristics of infrared radiation and various characteristics in the process of propagation, using infrared detector to perceive the spectral characteristics of physical processes such as infrared radiation or absorption of objects, we can measure different attributes and characteristics of objects, such as object temperature, which is called infrared measurement technology. The non-contact temperature sensor is made of the principle that the radiant energy of the object changes with the temperature.
According to the working principle, infrared detector can be divided into two categories: thermal detector and photon detector. Among them, the thermal detector is mainly divided into three types: thermocouple / thermopile, bolometers and pyroelectric; the photon detector is mainly divided into intrinsic, extrinsic, free carriers and quantum wells.
In the most widely used field of infrared detector temperature measurement application, thermocouple / thermopile detector based on thermoelectric effect (or Seebeck effect) can be used to realize temperature measurement. The temperature measurement principle of thermocouple is: if two different materials or objects a and B with the same material and different work escaping are connected at the hot end (hot junction area), and open at the cold end (cold junction area), the temperature difference between the hot end and the cold end is ? THC, then a thermoe |
