Visual Testing (VT)
Visual testing is one of the fundamental NDT methods utilised. It is based on obtaining information about the tested material with the help of visual observations or through the use of optical aids and measuring instruments.
Visual testing is used to evaluate the condition and quality of a weld or component by detecting discontinuities and deviations of any size and shape. When utilising optical aid these deviations can be as small as 0.1mm.
Visual testing is usually performed with the naked eye or utilising a variety of different aids such as conventional magnifying glasses or advanced remote CCTV systems and borescopes.
Where a suspect case has been identified further visual inspection can be carried out in the form of micro and macro inspections where an examination is carried out from less that 20x (macro examination) and 50x up to 1,500x (micro examination) in order to assess the structure of a material.
Key points:
- Requires good visibility and working conditions and high skill level
- Requires minimal low cost equipment in normal cases
- Can be carried out at every stage of material production to ensure quality control and compliance
- CSWIP 3.1