Infrared Thermography
Infrared thermography (IRT) is a non-contact, non-destructive testing method that uses thermal cameras to detect infrared radiation emitted by objects, converting it into visible thermograms to visualize surface temperature distribution and identify thermal anomalies, enabling early detection of equipment faults.
In manufacturing and asset reliability, IRT is performed on live electrical systems, rotating machinery, refractory linings, and process pipelines to detect abnormal temperature rises or hot spots before functional failure occurs. Thermal inspection data, including thermograms and temperature readings, are logged into CMMS systems like ServiceGrid to trigger predictive maintenance work orders, track asset health trends, and schedule repairs based on thermal deviation thresholds. As a passive condition-based maintenance tool, it allows remote inspection of large areas quickly without physical contact or electromagnetic interference.
- Missed electrical degradation: Failure to detect loose connections, corroded terminals, or overloaded circuits in breaker panels, leading to arc flash, fire, or power loss.
- Bearing and motor overheating: Ignoring friction-induced heat in rotating bearings or motors, resulting in catastrophic seizing, shaft damage, or motor burnout due to lack of lubrication or misalignment.
- Refractory and insulation blind spots: Overlooking delaminations, cracks, or thermal bridging in refractory linings or pipe insulation, causing energy loss, process inefficiency, or safety hazards from exposed high temperatures.
What is the difference between active and passive infrared thermography?
Passive IRT, used in maintenance, measures naturally emitted radiation from operating equipment without external heating. Active IRT applies external energy, such as flash lamps, to induce thermal response for detecting subsurface defects in non-operating materials.
What is the optimal wavelength range for industrial thermography cameras?
Industrial cameras typically operate in the 0.7 to 14 μm infrared wavelength range, where radiation intensity correlates directly with object temperature for accurate surface mapping.
How does emissivity affect thermographic accuracy?
Emissivity, the efficiency of a surface to emit infrared energy, must be calibrated. Low-emissivity surfaces, like polished metal, reflect ambient radiation, causing false temperature readings if not corrected with emissivity tape or paint.