<title>Cooling down thermography: principle and results for NDE</title>

Abstract

Cooling down thermography represents a novel approach to thermal nondestructive testing: the sample is previously heated in an oven in order to obtain a uniform temperature, then it is exposed to a lower ambient temperature. An IR camera monitors the surface temperature decay in order to reveal internal defects. While this approach presents clear disadvantages in terms of versatility, it allows for a faster and deeper penetration in the sample, and it has therefore mainly been used in order to reveal deep defects in insulating materials.