Visual Test

Visual testing (VT) is the most basic non-destructive testing method used in welded joints to evaluate the surface quality and visible defects of weld seams. In this method, the weld surface is examined directly by eye without using any special device or in some cases with simple auxiliary tools such as a magnifying glass or endoscope.

The aim of the visual test is to detect visible defects on the weld surface, such as cracks, pores, slag residue, melting errors, surface irregularities. Visual testing is usually performed as the first assessment before other non-destructive testing methods. Thus, if there is a visible defect on the weld surface, further tests may not be necessary.

Steps of Visual Testing:

Surface Cleaning: Before visual inspection, the weld surface must be cleaned and any paint, dirt, oil or weld spatter must be removed.

Visual Inspection: The weld seam is examined visually in accordance with the standards and acceptance criteria. A detailed examination is performed with the naked eye or with tools such as a magnifying glass and mirror.

Measurement and Recording: Measurements such as weld width, height, root transition can be made and the detected defects or deficiencies are recorded.

Advantages:

It is a fast, easy and low-cost method.

It allows a general assessment of the surface quality of the weld.

It does not require any additional equipment or can be done with simple tools at most.

Limitations:

It can only detect surface defects, it is not suitable for internal defects.

Since it is a visual inspection, the results may vary depending on the experience and knowledge level of the operator.