Visualization Technique of Surface Slit Crack by Thermal Infrared Radiometer

Abstract

An infrared radiometer has been used for detecting and visualizing surface cracks and scratches of metal and graphite. The image of surface flaw can be displayed on the CRT under a remote sensing condition by using the infrared radiometer. Two dimensional distribution of radiation energy emitted from the cracks shows an isothermal line image on the CRT by radiation cavity effect. The width and depth of surface cracks can be measured with increase in the radiation temperature.