How does it work to measure temperature using infrared?
All objects with temperatures above zero (-273.15 ℃) are constantly emitting infrared energy into the surrounding space. Its radiation characteristics, radiation energy size, wavelength distribution, etc. are closely related to the surface temperature of the object. Conversely, by measuring the infrared energy radiated by an object itself, its surface temperature can be accurately determined, which is the mechanism of infrared radiation temperature measurement.
Like other living organisms, the human body also radiates and releases infrared energy in all directions, with a wavelength generally ranging from 9-13 μ m and located in the near-infrared band of 0.76-100 μ m. Due to the fact that light within this wavelength range is not absorbed by air, the infrared radiation emitted by the human body is not affected by environmental factors, but only by the amount of energy stored and released by the human body. Therefore, as long as the infrared energy radiated by the human body itself is measured, the surface temperature of the human body can be accurately determined. The human infrared temperature sensor is designed and manufactured based on this principle.
The working process of an infrared thermometer: The infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, display output, and other components. The optical system collects the infrared radiation energy of the target within its field of view, and the size of the field of view is determined by the optical components and position of the thermometer. The infrared radiation emitted by the measured object first enters the optical system of the thermometer, and then the incident infrared radiation is converged by the optical system to make the energy more concentrated; The concentrated infrared radiation is input into the photodetector, and the key component of the detector is the infrared sensor, which is responsible for converting optical signals into electrical signals; The electrical signal output from the photodetector is converted into the temperature value of the measured target after being amplified and processed by the signal processing circuit according to the algorithm and target emissivity correction inside the instrument.
