Fast spatial resolved thermography

In this experiment the IR converter is combined with an intensified CCD camera which features short exposure times. The cooling off of a metal foil is studied with this system. The set-up consists of a metal band (width: 2 mm; length: 6 mm) which is heaten by a short current pulse. The image of this foil is projected by an bariumflurid lens system onto the input of the IR converter. The glow of the gas discharge is recorded by the intensified CCD camera.

Figure of images of the "foil experiment".

The figure shows the temporal evolution of the metal foil within the first 500 ms. The exposure time of all images is 1 ms. Within the first 30 ms the temperature of the foil is increasing. The time intervall corresponds to the heating of the foil (30 ms). Thereafter the temperature is decreasing. Calibrating the output intensity of the IR converter by means of a black body source it is possible to assign a temperature to the coulor of the images.

Calibrated output intensity of the IR converter

The upper graph is a calibrated curve of the output intensity. By means of this curve coulors of images correspond to a well defined temperature.

Figure of a calibrated image

The image represents a shot of the metal foil in which the temperature of selected areas is indicated.