What are the factors affecting the measurement accuracy of infrared thermometers?
1. Measure angle
In order to ensure accurate measurement, the instrument should try to measure along the normal direction of the measured object surface (perpendicular to the measured target surface) as much as possible.
If it cannot be guaranteed to be in the normal direction, measurements should also be taken within a 45 ° angle to the normal direction, otherwise the instrument display value will be lower.
2. Environmental temperature
The instrument should be used strictly according to the environmental temperature indicated in the technical specifications of the instrument. Beyond this range, the measurement error of the instrument will increase, and even damage it.
When the ambient temperature is high, air cooling, water cooling devices or thermal protection sleeves can be used. Thermal protection sleeves can enable the instrument to function normally in environments up to 200 ℃.
When a handheld thermometer is used in an environment with a large temperature difference from another environment, it will temporarily reduce the accuracy of the instrument, in order to obtain ideal measurement results;
The instrument should be left at the work site for a period of time (recommended at least 30 minutes) to reach equilibrium between the instrument temperature and the ambient temperature before use.
3. Air quality
Smoke, dust, and other pollutants in the air, as well as unclean lenses, will prevent the instrument from receiving sufficient infrared energy to meet measurement accuracy, and the measurement error of the instrument will increase.
Therefore, it is important to keep the lens clean regularly, as an air blower can help prevent contamination of the lens.
4. Electromagnetic interference
Instruments should be kept as far away as possible from potential sources of electrical interference, such as electric 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, using external protective conduits, rigid conduits are better than flexible conduits. Do not introduce the AC power of other devices into the same conduit.
5. 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 path, causing measurement errors.
In order to overcome the impact of environmental radiation, the first step is to avoid direct entry of environmental radiation into the optical path. The measured target should be filled with the instrument's field of view as much as possible. For indirect interference from environmental radiation, occlusion can be used to eliminate it.
6. Field of view and target size
Ensure that the target enters the instrument's measurement field of view.
The smaller the target, the closer it should be. In actual measurement, in order to reduce errors, the size of the target can be made more than twice the size of the field of view spot.
