Environmental radiation of infrared thermometer
When conducting infrared detection of outdoor power equipment, the infrared radiation received by the detection instrument not only includes the radiation emitted by the corresponding part of the tested equipment itself, but also includes reflections from other parts of the equipment and the background, as well as direct sunlight radiation. These radiations will cause interference with the temperature of the tested part of the equipment and bring errors to fault detection. In order to reduce the impact of environmental and background radiation, the following countermeasures should be taken: for on-site infrared testing of outdoor electrical equipment, it is best to choose to conduct it on cloudy days or during dark hours around sunset. This can prevent the direct incidence, reflection, and scattering of solar radiation. For indoor equipment, it is recommended to turn off the lighting and avoid other radiation effects.
For highly reflective equipment surfaces, appropriate measures should be taken to reduce the impact on solar radiation and surrounding high-temperature object radiation. Alternatively, change the detection angle to find the best angle to avoid reflection for detection.
To reduce the impact of solar radiation and surrounding high-temperature background radiation, appropriate shielding measures can be taken during detection, or appropriate infrared filters can be installed on infrared thermal imaging instruments to filter out solar and other background radiation.
Select instruments with appropriate parameters and detection distances for testing, so that the tested equipment parts are filled with the instrument's field of view, thereby reducing background radiation interference.
The infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, display output, and other components. The optical system gathers the external 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. The infrared energy is focused on the photodetector and the corresponding electrical signal is converted into the temperature value of the target by the amplifier and signal processor circuit, and corrected according to the algorithm and target emissivity built-in in the instrument, as well as environmental temperature compensation. When measuring the temperature of a target using an infrared radiation thermometer, the first step is to measure the infrared radiation of the target within its wavelength range, and then the thermometer calculates the temperature of the measured target. The monochromatic thermometer is directly proportional to the radiation amount within the band, while the bicolor thermometer is directly proportional to the radiation amount between the two bands.
