Factors affecting the measurement accuracy of infrared thermometer

With the development of science and technology and the needs of modern industrial technology, temperature measurement technology has been continuously improved and improved. As the temperature measurement range becomes wider and wider, different temperature measurement instruments are manufactured according to different requirements, and infrared thermometer is one of them.

Infrared thermometer uses the principle of infrared transmission of numbers to sense the surface temperature of objects. It is easy to operate, especially for measuring high-temperature objects. Widely used, such as steel casting, furnace temperature, machine parts, glass and room temperature, body temperature and other surface temperature measurement of various objects.

When the infrared thermometer is used from one environment to another with a large difference in ambient temperature, the accuracy of the instrument will be temporarily reduced. In order to obtain ideal temperature measurement results, the instrument should be left at the work site for a period of time (recommended (at least 30 minutes) to allow the temperature of the instrument to reach equilibrium with the ambient temperature before use.

    1.Electromagnetic interference

    The instrument should be kept as far away from potential sources of electrical interference as possible, such as electrical equipment with large load changes. Use shielded wires for the output and input connections of online instruments and ensure that the shielded wires are well grounded. In strong interference environments, use external protective conduits. Rigid conduits are better than flexible conduits. Do not route AC power from other equipment into the same conduit.

    2. Air quality

    Smoke, dust and other pollutants in the air as well as unclean lenses will prevent the instrument from receiving enough infrared energy to meet the measurement accuracy, and the instrument's measurement error will increase. Therefore, keep the lens clean regularly and an air purifier will help keep the lens free from contamination.

    3. Field of view and target size

    Make sure that the target enters the measuring field of view of the instrument. The smaller the target, the closer it should be. In actual measurement, in order to reduce the error, the size of the target is generally made to be more than twice the size of the field of view spot.

    4. Environmental radiation

    When there are other high-temperature objects, light sources or solar radiation around the measured target, these radiations will directly or indirectly enter the measurement light path, causing measurement errors. In order to overcome the influence of environmental radiation, we must first prevent environmental radiation from directly entering the optical path, and try to make the measured target fill the instrument's field of view. Indirect interference from environmental radiation can be eliminated by blocking.

    5.Measure the angle

    In order to ensure accurate measurement, the instrument should try to measure along the normal direction of the surface of the object being measured (perpendicular to the target surface being measured). If it cannot be guaranteed to be in the normal direction, the measurement should also be carried out within an angle of 45° from the normal direction, otherwise the instrument display value will be low.