In all effective NDT methods visual Inspection is most widely used among all NDT methods.It is simple, easy to apply and quickly carried out when comparing to other methods, it is low in cost. We can find only surface defects in test components thus leading to an immediate rejection of the components and it saves time and money.
This method is done by the principle called Differential Variation. The various types of equipment’s used in visual testing is mirror, borescopes, magnifying lens, microscopes, optical flats, optical comparators.
The types of defects that we can detect in this method are