Accuracy

Accuracy

Choosing a thermal imager based on accuracy is generally less important with infrared cameras than when working with some other types of quantitative measurement tools. That’s not to say it’s irrelevant, but other parameters are more important.

Often in thermography, we are interested in differences temperature, which is a relative value, rather than an absolute one, so accuracy is less important. Secondly, calculating temperature from infrared energy is involves a large number of inputs including the distance-to-target, target size, iFOV, spot size (distance-to-spot ratio), wind/air movement ....

Even more significant, values like emissivity and reflected apparent temperature measured which are input by the thermographer have the ability to drastically change the calculated temperature. For example, a small inaccuracy in the emissivity entered for a metal object will always throw the temperature reading far outside of the range of even the least accurate imagers.

So when absolute surface temperature readings are required, it’s much more important to ensure that the choice of camera, the ‘setup’ (target size, distance-to-target, iFOV, lens choice, detector size, thermal sensitivity) are suitable and that the thermographer understands how to measure and input the variables that are used to calculate temperature from the infrared energy emitted by the target.