Theory and Basics
Temperature measurement can be divided into two categories: contact and non-contact. Contact thermocouples, RTDs and thermometers are the most common in temperature measurement applications. Since they measure their own temperature they must touch the target and their response is relatively slow, but they are cheaper. Non-contact temperature sensors measure the infrared energy emitted by the target, they are fast responding and are typically used to measure moving or intermittent targets, targets in a vacuum, and targets that are inaccessible due to harsh environments, structural limitations, or safety hazards. Their cost is high, but in some cases they are comparable to non-contact devices. Infrared radiation was discovered by Isaac? Sir Isaac Newton in 1666, who isolated electromagnetic energy from sunlight by passing white light through a glass prism that broke the white beam into the colors of the rainbow. in 1800, Sir William Herschel further measured each of the colors of the rainbow. Sir Herschel further measured the relative energy of each color. He also discovered energy beyond visible light.
In the early 1900s, Planck, Stephan, Boltzmann,
Wien and Kirchhoff further characterized the activity of the electromagnetic spectrum and developed quantitative data and equations for determining energy in the infrared.
I can't tell you the details, look for the technical references on their official website yourself, they talk more carefully.
I hope this helps. I hope you will adopt it.
References:
Omega's Chinese website