What affects the accuracy of the measurement of an infrared thermometer?
Because infrared temperature measurement technology is widely used in industry and other fields, therefore, its measurement accuracy has also put forward higher requirements. Non-contact infrared body thermometer in the function and technology is more and more perfect, however, there are factors that affect its accuracy, if not pay more attention, will lead to infrared thermometer measurement accuracy deviation, then, what are these influencing factors?
Measurement angle
In order to ensure accurate measurement, the instrument should try to measure along the surface of the object being measured in the direction of the normal (perpendicular to the surface of the target being measured) for measurement. If you can not guarantee in the direction of the normal line, should also be in the direction of the normal line into 45 ° angle for measurement, otherwise the instrument display value will be low.
Ambient temperature
The instrument should be used in strict accordance with the ambient temperature indicated in the technical specifications of the instrument, beyond which the measurement error of the instrument will increase or even be damaged. When the ambient temperature is high, air-cooled, water-cooled device or thermal protection sleeve can be used, the thermal protection sleeve can make the instrument in the environment up to 200 ℃ normal use.
Handheld thermometer from an environment to another environment with a large difference in ambient temperature when used, will lead to a temporary reduction in the accuracy of the instrument, in order to get the ideal measurement results, the instrument should be placed on the job site for a period of time (recommended at least 30 minutes) so that the instrument temperature and the ambient temperature to reach equilibrium before use.
Air Quality
Smoke, dust and other pollutants in the air as well as uncleaned lenses will prevent the instrument from receiving enough infrared energy to meet the measurement accuracy, and the measurement error of the instrument will increase. Therefore, it is best to keep the lens clean frequently, and an air purger helps to keep the lens free from contamination.
Electromagnetic interference
The instrument should be kept as far away as possible from potential sources of electrical interference, such as motorized equipment with large load variations. Use shielded cables for the output and input connections of in-line instruments and ensure that the shielding is well grounded. In strong interference environments, use external protective conduit, rigid conduit is better than flexible conduit. Do not introduce AC power from other equipment into the same conduit.
Environmental radiation
When the measured target is surrounded by other objects with higher temperature, light sources or radiation from the sun, these radiations will directly or indirectly enter the measurement optical path and cause measurement errors. In order to overcome the impact of environmental radiation, first of all, to avoid environmental radiation directly into the optical path, should try to make the target to be measured to fill the field of view of the instrument, for the indirect interference of environmental radiation, can be used to eliminate the method of blocking.
Field of view and target size
To ensure that the target into the instrument measurement field of view. The smaller the target, the closer it should be. In actual measurement, in order to minimize the error, it is best to make the target size of the field of view spot more than twice the size.
