What is the infrar

Generally speaking, infrared light generally refers to infrared. Infrared is an electromagnetic wave with a frequency between microwave and visible light. It is a general term for the radiation with a frequency of 0.3thz ~ 400thz in the electromagnetic spectrum and a wavelength of 1mm ~750nmin vacuum. It is invisible light with a lower frequency than red light.

 

 

 In physics, substances above absolute zero (i.e. - 273.15 ℃) can produce infrared (and other types of electromagnetic waves). Modern physics calls it blackbody radiation (thermal radiation). Medical infrared can be divided into two categories: near infrared and far infrared. Infrared has thermal effect and can resonate with most molecules to convert light energy (energy of electromagnetic wave) into intramolecular energy (heat). The heat of the sun is mainly transmitted to the earth through infrared.

 In the electromagnetic spectrum, the radiation located outside the red light, whose frequency is lower than the visible light and higher than the microwave is called infrared. Infrared is invisible to the naked eye and belongs to invisible light. Infrared is one of the many invisible rays of the sun. It was discovered by British scientist Herschel in 1800. It is also known as infrared thermal radiation. It has strong thermal effect. He separated the sunlight with a prism and placed a thermometer at the color band of various colors to try to measure the heating effect of light of various colors. It was found that the thermometer on the outside of the red light warmed up the fastest. Therefore, it is concluded that there must be invisible light outside the red light in the solar spectrum, which is infrared. It can also be used as a transmission medium. The English name of infrared is infrared, in which infra - means "below, under". 

 Infrared can be divided into three parts, namely near infrared (high frequency infrared, high energy) and wavelength (3 ~ 2.5) μ m～(1~0.75) μ M; Medium infrared (medium frequency infrared, moderate energy), wavelength (40 ~ 25) μ m～(3~2.5) μ M; Far infrared (low frequency infrared, low energy), wavelength 1500 μ m～(40~25) μ M. Infrared (especially far infrared) has a strong thermal effect. It can resonate with most inorganic molecules and organic macromolecules in organisms, accelerate the motion of these molecules and rub each other, so as to generate heat. Therefore, infrared can be used for heating and molecular spectroscopy.