Temporal resampling of time-varying infrared images sequences

Abstract

The paper presents an effective method for the measurement, using a standard infrared camera working at 25 Hz frame rate with 320256 pixels full frame, of very fast temperature transients (i.e., having a bandwidth of 10 kHz or more) which, in principle, would require a much faster acquisition rate. The proposed method is based on triggering multiple time-delayed acquisitions (MTDA) of the observed thermal phenomenon, which has to be reproducible, by means of a very precise and stable programmable digital micro-controller and by reconstructing the time domain IR sequence using the frames acquired at each trigger event. The method could find application in assessing the reliability of power electronic devices and, in particular, to measure dynamically temperature distribution over the source metal of Power MOSFETs or IGBTs, which feature very fast thermal transients, even in the hundreds of microsecond scale and might develop local hot spots as a consequence of aging or failures.