RSNV: What is thermal infrared?

What is thermal infrared?

Generally, the wavelength of electromagnetic wave (visible light) that can be sensed by human eyes is between 400 and 700 nm. The infrared wavelength for monitoring auxiliary lighting is 850 nm, and the part with wavelength from 2.0 to 1000 μ m is called thermal infrared. Objects around us emit visible light only when their temperature is above 1000 ℃. In contrast, all the objects around us whose temperature is above absolute zero (- 273 ℃) emit thermal infrared continuously. Therefore, thermal infrared (or thermal radiation) is the most extensive radiation in nature. Infrared radiation, like light wave and radio wave, is a kind of electromagnetic wave.

The propagation of thermal radiation

The infrared of thermal radiation is a kind of electromagnetic wave, which has all the physical characteristics of electromagnetic wave. When the electromagnetic wave passes through the atmosphere, it will be reflected, absorbed and scattered by the atmosphere, Therefore, the energy of electromagnetic wave passing through the atmosphere is attenuated, and those bands with high transmittance which are less reflected, absorbed and scattered through the atmosphere become the atmospheric window. The spectral bands of the atmospheric window mainly include: microwave band (300-1ghz), thermal infrared band (814um), mid infrared band (3.5-4um), visible and near infrared band (4-25um), infrared visible and ultraviolet.

The application of infrared radiation

Infrared radiation is used in industrial, scientific, military, commercial, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected.Infrared radiation is used in industrial, scientific, military, commercial, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected.

Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect the overheating of electrical components