PULSE PHASE INFRARED THERMOGRAPHY

An approach is proposed which combines simultaneously advantages both of pulse (PT) and modulated infrared thermography. In a nondestructive evaluation perspective, the specimen is pulse heated as in PT and the mix of frequencies of the thermal waves launched into the specimen is unscrambled by performing the Fourier transform of the temperature ev olution over the field of view. Of interest is the maximum phase image with many attractive features: deeper probing, less influence of surf ace infrared and optical characteristics, rapid image recording (pulse heating, surface-wide inspection), and the possibility to inspect hig h thermal conductivity specimens. Several results are presented and th e theory is discussed as well. (C) 1996 American Institute of Physics.