I am writing this article in August, although it won’t be published until a later date. I am celebrating my 86th birthday this month and this will be something like my 145th submission of ‘Letter from America’. It finds me in a reflective mood as I look back on my last 61 years in the USA.

The COVID-19 pandemic has forcibly interrupted my employment, although I am still active on American Society for Nondestructive Testing (ASNT), BINDT and American Petroleum Institute (API) committees, and I continue to provide information and advice to my former colleagues.

I emigrated to the USA in 1960 at the age of 25, after teaching maths and science in Scotland for two years and then spending three years in Burgundy, France, in the wine industry.

By sheer happenstance, I found myself in Tulsa, Oklahoma, working for an engineer who was a pioneer in the early application of ultrasonic technology to industrial applications. I have covered some of my adventures in the early and primitive applications of ultrasonics and non-destructive testing (NDT) in previous ‘Letter from America’ submissions.

I can also look back on the amazing advances in the technology of NDT. The current technology is unimaginable viewed from the perspective of the 1960s. The technology has evolved from early electronics using valves (tubes) and electric power cable dependence in the early days to battery power instrumentation using transistors and now to robotic data collection.

The first ultrasonic instruments used vacuum tubes as switches and, although the tubes worked, they had many problems. Unfortunately, the tube was inefficient as a switch. It consumed a great deal of electrical power, gave off much heat and was notoriously unreliable and prone to failure. Early technicians learned which tube failure caused a recognisable display effect and were able to replace the specific tube (valve).

The invention of the transistor was one of the important developments leading to the personal computer revolution and the equivalent development of ultrasonic instrumentation. The transistor, which essentially functions as a solid-state electronic switch, replaced the less-suitable vacuum tube. Because the transistor was so much smaller and consumed significantly less power, a system built with transistors was also much smaller, faster and more efficient than a system built with vacuum tubes. This conversion from tubes to transistors began the trend towards miniaturisation that continues to this day.

The NDT pioneers have little compassion for the technicians who complain about the ‘heavy’ instruments they have to pack around.

Transducers, couplants and communication technology have all made the transition to greater efficiency over these 60 years. The evolution in access technology is also dramatic; from rope ladders, flotation rafts, crane-operated baskets to safety-certified rope access and drones.

Technician safety is now a priority. My early experience did not include the use of safety belts, hard hats, ear plugs, hole watch, gas-free certification and personal protective equipment (PPE). Asbestos in insulation had not been recognised as a source of lung cancer and was often removed from piping, to obtain access for inspection, without concern for the release of fibres into the air.

No, it was not the ‘good old days’. It was the beginning of the inevitable process from the introduction of NDT technology to the technical progression towards new technology. It continues in today’s NDT world with the introduction of fourth generation (4G) technology, robotic NDT information acquisition and fixed monitoring assets. Remote and computer-generated evaluation will be part of its inevitable progression. It will require a new generation of NDT technicians with advanced skills and technical training to meet the advanced technical requirements of 4G NDT.

I plan to continue monitoring the progress of NDT and try to keep abreast of the applied science. Above all, I plan to continue reporting the NDT activities in North America for the foreseeable future.

I would love to get feedback from readers of NDT News.

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