Electric thermal inspection of metal sheets

Abstract

An electrothermal method of nondestructive inspection of conducting materials is proposed and tested experimentally. This method is based on filming the IR emission of the surface induced in a sheet sample excited by a millisecond current pulse. Subsequent computer processing of the nonstationary thermalfield patterns reveals millimeter and submillimeter defects and provides an opportunity to estimate their geometrical parameters and the temperature-diffusivity coefficient of the material.