Automation in Non-Destructive Testing - The Changing Role of the Operator

Introduction

To understand the current non-destructive testing (NDT) world, it is perhaps a good idea to look back at things historically. By doing this, changes which have taken place become apparent, and very soon one can conclude that this is actually quite significant! Obviously, this is true for all industries but certainly also in NDT. This article aims to address the ever changing role of the operator in this perspective.

The oldest and most used non-destructive test is visual inspection. To test whether the quality of a product is in accordance with what was actually agreed upon between manufacturer and client, simply looking at the product already says a great deal. Neanderthal man would probably not take delivery of a clay pot with a big hole in the bottom without grabbing his bludgeon to explain a thing or two to the manufacturer. In relation to visual inspection, demands placed on the inspector are mainly a deep knowledge about the product and, obviously, visual acuity.

Visual Testing has, over time, become a full-fledged NDT method, in which using a wide range of tools has become common to aid interpretation. This began with simple, passive tools such as magnifying glasses.

Later on, capturing the level of quality (or lack thereof) with photography became more common. Nowadays, the simple use of digital photography is as common as Visual Testing itself!

Much more modern than visual inspection, as we had to wait for the discovery of radiation and its uses, Radiographic Testing is without a doubt the most commonly-used NDT method of this time.

Knowledge Remains Indispensable

After the discovery of Ionising Radiation, it suddenly became possible to look inside objects under test without damaging them. The application of Radiographic Testing, which is the use of an isotope or X-Ray tube, was relatively simple and could be taught quite easily to people with some education.

Obviously, correct interpretation of radiographic testing results of objects being tested is essential. Furthermore, in-depth knowledge about ionising radiation to enable its safe use in industrial radiography is necessary. The digital revolution has now entered the field of X-Ray as well, where more and more traditional film radiography methods are being replaced by digital images.