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Learn about infrared thermometers

Oct. 07, 2023

In this article, we are presenting temperature measurement in a completely different way than in the past. Instead of measuring temperature by holding a mercury thermometer under the armpit, nowadays body temperature measurement is much more advanced, and they are able to measure the value of people's body temperature just by walking in front of the thermometer. How do these thermometers measure body temperature? How do they work? This article will give a brief introduction.

First, we need to know the concept that any object with a temperature above 0K (-273.15°C) emits thermal radiation, which is also known as electromagnetic waves, and that the higher the temperature of the object, the stronger the thermal radiation emitted. This means that any object that is on Earth emits thermal radiation. Infrared thermometry is based on this principle. It captures the thermal radiation emitted by the human body and displays the body temperature based on the strength of the thermal radiation. The specific temperature measurement process of infrared thermometer:
Firstly, the captured infrared radiation of the measured object is sent to the infrared detector through the optical system, and the detector converts the thermal radiation into a voltage signal, after which the voltage signal is converted into a temperature value for output through the processing of the readout circuit. Figure 2 shows an infrared thermography picture.

From the working principle and working mode of infrared thermometer, it has the outstanding advantages of fast measurement speed, non-contact, etc. These advantages make the infrared thermometer play a great role in the prevention and control of the new crown epidemic.

Getting to know infrared technology, starting with infrared thermometers

Wide range of applications

In fact, the application of infrared technology is not only limited to measuring body temperature, it has more and wider application areas. What is more surprising is that infrared technology appeared much earlier than people think.

Infrared imaging technology has been in the public eye since as early as the 19th century. At that time, it was found that it was not only more convenient but also more effective to use infrared detectors to characterize the infrared radiation of astronomical stars. Later, infrared imaging technology showed strong potential for application in the military field, for which countries invested a great deal of human and material resources in the development of infrared technology. Since then, the development of infrared imaging technology is more extensive, infrared imaging, infrared tracking, infrared early warning, infrared countermeasures, infrared guidance and other technologies, such as sub ah military has been widely used. After 1970, infrared technology gradually shifted from the military field to the civilian field. A variety of advanced infrared technology, such as infrared remote sensing, infrared temperature measurement, infrared detection, infrared security and other widely used in various industries.

Powerful application technology

Infrared remote sensing, the technology uses infrared cameras, infrared scanners and other infrared devices to detect infrared radiation from vegetation and other places at a distance, and then analyzes the differences in the infrared characteristics to determine the nature of the features, the distribution and status of the information. Infrared remote sensing technology has a wide range of applications, one of which we are more familiar with is the detection of air pollution in the city. Detection, first through the infrared remote sensors to collect the city's spectral information, and then based on different spectral characteristics, through the computer real-time counter-performance of the city's main pollutants and their spatial and regional distribution and so on.

Infrared security, at night or under adverse weather conditions, ordinary visible light cameras can not work properly, the observation distance is greatly shortened, if the use of artificial lighting, it is easy to expose the target; if the use of micro-light night vision equipment, still need external light illumination, such equipment in the city can still work, but in the field, due to the observation of the distance shortened dramatically, which will lead to the equipment observation effect deterioration or even can not be normal work. This reflects the importance of infrared security equipment.

An infrared camera is able to convert the invisible infrared energy emitted by an object into a visible thermal image, where different colors represent different temperatures of the object under test. Because the thermal imaging camera can actively receive infrared radiation emitted by the target, so whether it can work properly, with the surrounding weather conditions have nothing to do, coupled with the thermal imaging camera has a better stealth effect, and therefore in the night security monitoring, fire monitoring and other security areas have a wider range of applications.

Take fire monitoring as an example. Large forest fires are often started by inconspicuous hidden fires, and it is difficult to detect the first signs of such hidden fires with the existing common methods. By using infrared cameras, these hidden fires can be quickly and effectively detected, the location and scope of the fire can be accurately determined, and the point of ignition can be found through the smoke.

Infrared anti-counterfeiting, this technology is often applied to the manufacture of anti-counterfeiting inks. Infrared anti-counterfeiting ink is usually made by adding one or several materials that absorb near-infrared light into the ink, and in actual use, only the anti-counterfeiting ink is employed to draw the desired information on the prints. These messages have no trace under visible light conditions, but can be decoded by infrared detection instruments.

Advanced infrared technology has brought convenience and speed to human life. CLZ Optical Co., Ltd. is committed to producing professional optical components, from design to production to sales integration, the main products include spherical lenses, including optical domes, plano-convex lenses, optical windows, optical prisms, mirrors and so on. We also could provide OEM service, use many kinds of substrates such as sapphire, fused silica, silicon etc. Our optical domes, optical prisms, mirrors, etc. can be used for the infrared applications mentioned in this article. Please contact us if you have any needs!

Getting to know infrared technology, starting with infrared thermometers