Infrared thermometer structural characteristics and principal analysis
The infrared rays received from the measured object are focused on the detector through the lens through the filter. The detector generates a current or voltage signal proportional to the temperature through the integration of the radiation density of the measured object. In the electrical components connected thereafter, the temperature signal is linearized, the emissivity area is corrected, and converted into a standard output signal.
In principle, there are two types of portable thermometers and fixed thermometers. Therefore, when choosing a suitable infrared thermometer for different measurement points, the following characteristics will be the main ones:
1. Aimer
The collimator has this effect, and the measuring block or measuring point pointed by the thermometer can be seen, and the collimator can often be used for large-area measured objects. For small objects and long measuring distances, sights with instrument panel scales or laser pointing points in the form of light-transmitting lenses are recommended.
2. Lens
The lens determines the measured point of the pyrometer. For large-area objects, a pyrometer with a fixed focal length is generally sufficient. But when the measurement distance is far from the focus point, the image at the edge of the measurement point will be unclear. For this reason, it is better to use a zoom lens. Within the given zoom range, the thermometer can adjust the measurement distance. The latest thermometer has a zoomable replaceable lens. The near lens and the far lens can be replaced without calibration re-inspection. .
3. Sensors, i.e. spectral receivers
Temperature is inversely proportional to wavelength. At low object temperatures, sensors sensitive to long-wave spectral regions (hot-film sensors or pyroelectric sensors) are suitable, at high temperatures, short-wave sensitive sensors composed of germanium, silicon, indium-gallium, etc. will be used Photoelectric Sensors.
