Infrared Thermography Essentials
Infrared (IR) thermography has become an essential tool in many Predictive Maintenance (PdM) Programs. Infrared cameras have become user-friendly and plentiful in the marketplace, but there is still a lot to learn about thermography and proper camera operation.
These cameras may look easy to use—just “point and shoot” — and whatever data you hoped to find readily appears and may suggests that no troubleshooting skills are needed or training is required. On the contrary!
Diagnostic and operational errors may cause substantial problems for everyone because they start a chain reaction that can be not only embarrassing for the IR PdM technician or engineer but also expensive for both you and the organization you work.
Albeit very simple considerations, below are a few things to keep in mind and make part of any IR standard operating procedure (SOP). Remember the following
The first basic step toward correct thermography is FoRD “Focus, Range and Distance”. Fundamentally if the image is out of focus, the temperature out of range or the target too far away to resolve, the result will be inconclusive. The information one may extrapolate from a thermo-gram is crucial to a proper diagnosis and must be as precise as possible. Getting no data is less dangerous than getting bad data.
The second basic step is for the Thermographer to understand and adjust for emissivity and reflectivity. By carefully evaluating the area of inspection, these two factors may have a direct effect on proper interpretation of a thermo-gram.
Careful consideration of the two basic steps will ensure credibility in a PdM program using thermography, and also ensure correct assessments are made.