It is the oldest non-destructive testing method. Visual inspection is the control of the material to be tested using direct eye or intermediate equipment. The most important requirement is that the amount of light is at an acceptable level. Before testing, the surface must be cleaned and checked with sufficient light. Before this, information such as production information, operating conditions and such information about the part should be examined.

Visual inspection is used to detect different surface discontinuities. Testing is performed using devices such as baroscopes to reach areas where direct eye contact cannot be reached.

Many people think that visual inspection will occur after production is complete. However, pre-weld and during welding checks will eliminate errors that will occur after welding and facilitate the end of production control process.