THERE is no universal solution for all infrared inspections with a thermal camera, also known as a thermal imager, says Comtest, the regional distributor of Fluke equipment. “You need to match your method to the type of equipment you’re inspecting and the level of detail you require,” the company advises. It has identified three typical methods that cover most situations:
1. Baseline thermography
2. Thermal trending thermography
3. Comparative thermography
Baseline thermography
Baseline thermography is an excellent place to start for just about any application. First, scan the equipment when it’s first commissioned or later in the lifecycle when it is working the way it should be, and then use that as a reference point for future inspections. Whether comparing the thermal images on the camera in the field or on a PC using software tools, this baseline approach paves the way to spotting anomalies down the road.
Thermal trending thermography
Once the baseline has been set, thermal trending inspections can be used to compare how temperature is distributed in the same components over time. This can help to detect declining performance over time so that downtime maintenance can be scheduled before the equipment ‘schedules’ it.
Comparative thermography
The thermal camera’s results from similar components under similar conditions can be compared with each other. This method relies on the idea that similar or identical components under similar loads are expected to have similar temperature profiles. “Once you have three or more components, picking up an anomaly is relatively easy,” according to Comtest. “There’s one more level of complexity to consider: Depending on the components being compared, the actual temperature difference that can be viewed as an anomaly will vary,” it adds.
