How to determine the optical resolution and signal processing of a handheld infrared thermometer
Determine optical resolution
The optical resolution is determined by the ratio of D to S, which is the ratio of the distance D between the thermometer and the target to the diameter S of the measurement spot. For example, the handheld infrared thermometer Ti213 in the infrared era has a distance coefficient of 80:1. If it is 80 centimeters away from the target, the diameter of the measurement range is 1 centimeter. If the thermometer must be installed far away from the target due to environmental conditions and needs to measure small targets, a high optical resolution thermometer should be selected. The higher the optical resolution, i.e. increasing the D: S ratio, the higher the cost of the thermometer.
Signal processing function:
Given that discrete processes (such as part production) are different from continuous processes, infrared thermometers are required to have multiple signal processing functions (such as peak hold, valley hold, and average) to choose from. For example, when measuring bottles on a conveyor belt, peak hold is used, and the temperature output signal is transmitted to the controller. Otherwise, the thermometer will read the lower temperature value between the bottles. If peak holding is used, set the response time of the thermometer to be slightly longer than the time interval between the bottles, so that at least one bottle is always under measurement.
The main consideration when choosing an infrared thermometer is
(1) Temperature range: Each model of thermometer has its specific temperature measurement range. The temperature range of the selected instrument should match the temperature range of the specific application.
(2) Target size: When measuring temperature, the target being measured should be larger than the field of view of the thermometer, otherwise there may be measurement errors. It is recommended that the size of the target being measured exceed 50% of the field of view of the thermometer.
(3) Optical resolution (D: S): The ratio of the diameter of the thermometer probe to the target diameter. If the thermometer is far away from the target and the target is small, a high-resolution thermometer should be selected.
