The electric infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, display output, and other components. The optical system gathers 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 their positions of the thermometer. Infrared energy is focused on the photodetector and converted into corresponding electrical signals. The signal is amplified and processed by a signal processing circuit, and converted into the temperature value of the measured target after being corrected according to the algorithm of the instrument's internal therapy and target emissivity.

1. Selection method:

In terms of performance indicators, such as temperature range, spot size, working wavelength, measurement accuracy, response time, etc; In terms of environment and working conditions, such as environmental temperature, windows, display and output, and protective accessories; Other options, such as ease of use, maintenance and calibration performance, and price, also have a certain impact on the selection of thermometers. With the continuous development of technology, the design and new progress of infrared thermometers provide users with various functions and multi-purpose instruments, expanding their choices.

2. Determine the temperature measurement range:

The temperature measurement range is an important performance indicator of a thermometer. Products such as TIME and Raytek have a coverage range of -50 ℃ -+3000 ℃, but this cannot be achieved by a single model of infrared thermometer. Each model of thermometer has its own specific temperature measurement range. Therefore, the user's measured temperature range must be considered accurate and comprehensive, neither too narrow nor too wide. According to the blackbody radiation law, the change in radiation energy caused by temperature in the short wavelength of the spectrum will exceed the change in radiation energy caused by emissivity error. Therefore, when measuring temperature, it is advisable to choose short waves as much as possible.

3. Determine target size:

Infrared thermometers can be divided into monochromatic thermometers and two-color thermometers (radiation colorimetric thermometers) based on their principles. For monochromatic thermometers, the area of the measured target should fill the field of view of the thermometer during temperature measurement. It is recommended that the size of the tested target exceed 50% of the field of view. If the target size is smaller than the field of view, the background radiation energy will enter the optoacoustic symbol of the thermometer to interfere with the temperature measurement reading, causing errors. On the contrary, if the target is larger than the field of view of the thermometer, the thermometer will not be affected by the background outside the measurement area.