Instead of information about the optical reflectivity of objects, thermal images contain information about the temperatures radiated off the surface of objects in the infrared wavelength range. Thermal images give valid information when looking, for example, for hot spots in power rails or water penetration in tunnels. Temperatures are usually visualized as grey scale images with lighter grey shades used for higher and darker shades used for lower than average temperatures.
The system uses one digital heat sink camera, controlled by a notebook computer, recording thermal images in both driving directions of the track recording vehicle. The camera of the thermal imaging system is housed in a weather proof enclosure, which, via an actuator mechanism, always follows the track center line. Images are recorded in selectable intervals, e.g. 2 m.
The software allows the temperatures of the thermal images to be measured in both real time and playback mode.
