Visual inspection, with or without optical aids, is the original method of NDT. Many defects are surface breaking and can be detected by careful direct visual inspection. Optical aids include low-power magnifiers, microscopes, telescopes and also specialised devices such as boroscopes, endoscopes and other fibre-optic devices for the inspection of restricted access areas. These devices can also be used with television camera systems. Much of the success of visual inspection depends on the surface condition and the lighting arrangements. Surface preparation such as cleaning and etching is often used and also surface replicas can be taken for both macro- and microscopic examination.
Many companies require an inspection of their products at various stages of the manufacturing process. This is done to ensure an acceptable product is produced for the customer. A majority of these inspections are performed by human employees, using only their eyes, often with minimal to no aid from assistive technologies.
The visual inspection process in the industry is a subjective task. Inspectors are often required to make absolute judgments when deciding to classify a component/weld as acceptable or in need of re-work. Due to this subjectivity, the job can be incorrectly classified as acceptable or scheduled for unnecessary re-work, leading to longer production times or higher costs. It is of interest for both manufacturers and customers of the engineering industry to improve the visual inspection process.
Hi-Tech visual inspectors employ different types of techniques from naked eye to use weld gauges, callipers, micrometres, magnifying devices, rulers and boroscopes etc. Our visual inspectors are experienced and certified to AWS-CWI/CWB level-II/III. They always follow approved Visual Inspection Procedures as per the requirements of Code/Standards and capable to make right decision.