There are many different forms of non-destructive testing (NDT). Some of them rely on modern equipment and technicians need the right training to provide them. However, there is still a place for classic visual inspection. It can be a useful, low cost option that can indicate if more expensive testing is necessary.
Eddy current testing
One of the cases where visual inspections can still be very effective is when you combine it with ECT testing. The problem with VI is that things like paint and other protective coating make it tricky to detect small discontinuities on the surface. Even with equipment like magnifiers and fibre optics, it is hard. Luckily, eddy current testing can look below these coatings and provide an accurate assessment of the condition.
ECT is also a good option for areas where access is tricky. There are many cases where it is not easy to inspect a part visually because of obstacles or hazards. Luckily, eddy current tests can detect flaws in these areas.
Another thing people can do is use visual inspection to enhance UT or vice versa. The benefits here are similar to those with ECT. For example, the ultrasonic testing can look below the surface of coatings and is suitable for use in areas where there are access problems. In addition, it is a good option for large infrastructures that would take a great deal of time to inspect visually.
Using visual inspection
It is still good practice to do visual inspections as part of quality checks and NDT. However, it is important to keep in mind that alone they will not provide a complete inspection. To increase the probability of detection (POD), it is important to combine these checks with more advanced ones like ECT or UT.
At Format NDT Ltd we understand the role visual inspection has to play and the potential drawbacks with it. Our team know when to use it and when it is better to rely on a different method.
So, if you have any questions or would like to arrange some form of testing, why not call us for advice? We will ensure you get the best service.