Visual and Optical Inspection
Visual and Optical inspection methods are generally used for two purposes, firstly to assess the part for general condition and possibly to establish suitability for other inspections methods, and secondly as a detailed method for inspection of visible effects, either by eye or using optical aids.
This prior inspection is often as important as using other more complex methods because a great deal of information about the condition of the part may be obtained at a glance.
Visual inspection of a crane
Uses optical aids to magnify, illuminate, see inside of, or see normally inaccessible areas by means of microscopes, borescopes, mirrors etc. Points tp watch when using optical aids are the increase in illumination required, restricted depth of field and field of view as magnification increases and shadow effects caused by spot type illuminators.