thermography

Thermography, or infrared thermography, is the science and technique of producing images that show surface temperature distributions by detecting infrared radiation emitted by objects. The resulting thermograms encode temperature as colors or gray levels. Infrared cameras sense wavelengths around 8 to 14 micrometers and convert radiation into electrical signals for display. Accurate measurements depend on the emissivity of the material, camera calibration, and atmospheric conditions.

There are two main approaches: passive thermography, which records natural thermal patterns during normal operation, and active thermography, which applies a controlled heat or cooling stimulus to reveal subsurface features through thermal contrast.

Applications are broad. In industry, thermography supports predictive maintenance of electrical and mechanical systems, insulation checks, and energy audits. In building science, it helps locate heat leaks and moisture. In medicine, thermography can map skin temperature patterns and is used as an adjunct tool in certain diagnostic workflows; it is not a standalone diagnostic method. In research, it enables non-contact temperature measurements in experiments.

Key limitations include that thermography measures surface temperature and can be affected by emissivity, reflections, distance, and atmospheric absorption. Proper interpretation requires calibration, knowledge of material properties, and standardized procedures.

Standards and guidance exist from ISO, ASTM, and IEC for thermography applications, data analysis, and safety. Advances continue in real-time imaging, higher resolution sensors, and advanced processing, expanding thermography’s utility while maintaining emphasis on correct methodology and context for interpretation.