However, with human inspectors there is always room for subjective interpretation. It's always more desirable to have quantifiable, statistically usable data, such as that obtainable with video inspection. Online machine vision systems usually combine one or more mounted cameras with a personal computer and specialized lighting to enhance the image as parts move past the camera. A frame grabber digitizes the video image so that the data can be stored and processed in the computer. Software often is customized for the application.
Computerization allows tolerances and critical attributes to be programmed in.
Rejects are recorded for later analysis and comparison. Essential offline inspection equipment includes a video camera and monitor, magnification lenses of various types, and metrology software to make the measurements. Often, video inspection gives manufacturers, for the first time, a real handle on quality in a statistically accurate format. We were using pin gages, micrometers, and occasionally optical comparators. Our edge measurements are no longer subject to inconsistencies in the way operators were doing the gaging.