Abstract
The problem inherent in the laser flash method is the involvement of comparatively large errors occasioned by the non-uniform radial distribution of the intensity of radiant heat emitted by the laser.
This error due to non-uniform heating is evaluated in this paper from the theoretical analysis made of a case where radiant heat with parabolic intensity distribution impinges pulsewise on one surface of a disk. The result indicates that much of the existing data reported in literature from measurements by laser flash are not very reliable, and that serious error in determining thermal properties can only be avoided by imposing severe limitations on the dimensions of the specimen, or else the results obtained from pulsewise and non-uniform heating of the specimen are subject to correction to account for the non-uniform heat distribution.
