Portable Infrared Thermometer Infrared Technology
A universally recognized understanding of its working principle lies in its temperature measurement mechanism. When an infrared thermometer is used for temperature measurement, the infrared energy emitted by the measured object is converted into an electrical signal on the detector through the optical system of the thermometer, and the signal is then converted into a visible temperature reading. Several key factors determine accurate temperature measurement, among which the most critical are emissivity, field of view, distance-to-spot ratio and spot position.
Emissivity
All objects reflect, transmit and radiate energy, and only radiated energy can reflect an object's actual temperature. When an infrared thermometer measures surface temperature, the device receives all three types of energy. Therefore, all infrared thermometers must be adjusted to capture only radiant energy. Measurement errors are usually caused by infrared energy reflected from external light sources.
Some infrared thermometers support adjustable emissivity, and the emissivity values of common materials can be found in standard emissivity tables. Other devices adopt a fixed preset emissivity of 0.95, which applies to most organic materials, painted surfaces and oxidized surfaces. For accurate measurement of such surfaces, attach a special adhesive tape or apply matte black paint on the measured area for compensation. After the tape or paint reaches the same temperature as the base material, measure the surface temperature of the tape or paint to obtain the true temperature of the object.
Distance-to-Spot Ratio
The optical system of an infrared thermometer collects energy from a circular measuring spot and focuses it onto the detector. Optical resolution is defined as the ratio of the distance from the thermometer to the measured object to the diameter of the measuring spot (D:S). A higher ratio means better optical resolution and a smaller measurable spot size.
Laser aiming is only used to assist in targeting the measuring point. The latest upgrades to infrared optics include a near-focus function, which enables precise measurement of small target areas and eliminates the interference of ambient background temperature.
Field of View
Ensure the target size is larger than the measuring spot of the infrared thermometer during detection; the smaller the target, the closer the measuring distance should be. For high-precision measurement scenarios, the target shall be at least twice the size of the measuring spot.
