| Visual Inspection

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. Spectra Asset Integrity Management cover all aspects of weld inspection using Visual inspection for the manufacturing, construction and commercial industries all over the UK.

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. In-situ metallography is also possible. Visual inspection is a vital part of an in-service inspection, which may or may not be backed up by other NDT methods. The examinations made are for fatigue cracks creep failure, corrosion, erosion, abrasion, mechanical damage, wear and tear, distortion, and poor workmanship.

High-speed visual inspection with automated output is used for the inspection of the surface of sheet material and television techniques may use enhanced image and pattern recognition methods.