The Principle and Use of an Infrared Thermometer
What is infrared radiation?
Infrared thermometers operate on infrared radiation. Infrared rays are the part of the electromagnetic spectrum that occupies between visible light. The electromagnetic spectrum is a group of different types of radiation. It includes gamma rays, X-rays, ultraviolet light, visible infrared radiation, microwaves, and radio waves. The wavelength of infrared light is greater than the wavelength of visible light. So infrared is a kind of invisible light. "Infrared" means "below the red line", indicating that this light can only be seen below the red light of the electromagnetic spectrum.
Contact and non-contact temperature measurement
The contact temperature detector must be temperature compatible with the target material. For example, mercury in a glass thermometer absorbs the temperature of the air and therefore expands with heat or contracts with cold. When a contact detector is placed in a different environment, it takes some time to adapt to the new environment. This is also called the detector's response time. In some application sites, it is impractical or impossible for the detector to contact the object being measured. Infrared detectors can measure temperature over long distances in a short period of time, so they are very practical in some situations.
Temperature measurement principle
Infrared detectors convert absorbed radiation into heat energy, thus increasing the temperature of the detector. And convert the temperature change data into electronic signals and amplify and display them.
Radiation principle
All objects are made of atoms that are constantly vibrating. The atoms with higher energy vibrate at a higher frequency. The vibrations of all particles, including these atoms, generate the electromagnetic spectrum. The higher the temperature of an object, the faster it vibrates and therefore the higher the spectrum of radiation energy. As a result, all objects constantly radiate outward at their own wavelength and frequency, and their wavelength and frequency depend on the object's own temperature and its spectral specific emissivity.
Visual range ratio and distance to diameter ratio
The visual range refers to the angle at which the instrument operates, which is determined by the individual's visual acuity. The visual range is the ratio of the distance between the instrument and the target to the diameter of the target. The smaller the target, the closer you should get to it. When the diameter of the target is small, it is important to move the thermometer closer to the target to ensure that only the target is being measured and not the surrounding environment.
laser visible
The laser spot is a point used to show the measurement area, rather than emitting something to be measured. This is a misunderstanding. The sensor is placed next to the laser module and is directly illuminated by the object. It forms the same light path as the laser.
