5 Common mistakes made during thermographic examinations

Heat images contain a great deal of useful information, provided they were taken and interpreted correctly. Some errors have a significant impact on the results.

We've compiled a list of the five most common mistakes made during thermographic exams so you can avoid them.

1. Wrong settings

You'd be surprised how many people have problems selecting the right camera settings. As a result, the end result is not representative and people draw wrong conclusions.
Mistakes are easily made. Consider, for example, an incorrect emissivity setting that causes ambient radiation to affect the measurements.
This again underscores the importance of proper training.

2. Object not in focus

A photographer taking a passport photo naturally wants the person to be in sharp focus. With thermography, it is no different. The object and heat pattern should be clearly identifiable. Blurred images lead to measurement errors and make it more difficult to identify problems.

You cannot solve this problem in post-production. So before metering, check that the focus of the thermal image is correct (along with the composition and temperature range).

3. Opening angle that does not fit the application

Choose the right thermal imager for the application. For example, if you are going to check high-voltage cables, you need a different lens than if you are visualizing the heat losses of a building.

The opening angle along with the distance from the object determines the Field Of View (FOV), which in turn affects details visible (Instantaneous FOV) and accuracy (Measurement FOV).

4. Misinterpretation

As mentioned earlier, proper thermal imaging camera settings are critical. But even when these are right, mistakes are often made while interpreting the images.

Consider building thermography, for example. Cold and hot spots can indicate air leaks, moisture problems, mold, missing insulation or pests. But it's also perfectly possible that nothing is wrong at all, but the temperature scales give a distorted picture.

A misdiagnosis can cost handsomely. Therefore, it is important for the thermographer - based on the images and the situation on site - to draw the right conclusions.

5. Measurements at the wrong time

Another common mistake is the timing. Make sure the measurements are taken at a representative time.

Suppose you want to analyze a factory fuse box. Then a measurement during working hours, when machines are running at full speed, will look completely different than if you measure after a working day or during partial production. Rain, dust and other external influences can also affect the results.

While thermography is a great way to detect defects, there are numerous other issues that can lead to misinterpretation or inaccurate measurements.

Therefore, please be well informed by us before you wish to purchase a measuring device, or if you wish to hire a thermographer.