thermal audit

Thermal inspection produces a lot of imagery and very few usable conclusions unless the platform, the sensor and the analysis method are matched to the physical question being asked. Detecting a failing insulation joint on a roof requires 0.04 degrees of thermal sensitivity and stable radiometric calibration, because the defect is a subtle discontinuity against a large gradient. Detecting a hot bearing in a conveyor needs far less thermal resolution but a much smaller minimum object size and the ability to work at 20 metres. The single-spectral thermal platform is the right answer for the second question and the wrong one for the first. We list sensor sensitivity, minimum object size and usable flight speed for each platform because those three numbers determine which inspections a given aircraft can actually perform.