A penetrameter, or image quality indicator (IQI), is a device used to measure the quality of radiographic images. Penetrameters consist of a piece of metal of simple geometric shape, with similar absorption characteristics as the weld to be tested. The thickness is generally 2% of the weld thickness. A penetrameter usually has three holes, the diameters of which are 1, 2, and 4 times the thickness of the penetrameter. The
penetrameters are placed on a test piece during setup and are radiographed at the same time as the test piece. Sharpness of the penetrameter features in the developed image is a measure of image quality. See RADIOGRAPHIC EXAMINATION.