For years, there has been a growing interest in digitising technology for testing and inspection services, but finding a technology that could match the industry requirements has proved a difficult task.

The development of ‘solid state arrays’ (digital photocamera technology) for industrial use has reached a turning point in recent times, as the quality is now capable of matching conventional film. This fired a broad range of developments in the non-destructive testing (NDT) sector all over the world.

For Applus, the goal was to push the limits to create the A+RTD tool that could become the best practice available on the market, rather than develop a device on par with the competition.

With this in mind, the company set out on a challenging path that started with a thorough scientific investigation into the sensor capabilities of various suppliers around the globe. This was done together with a leading research institute in Europe.

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Applus said that a new technology was found that has surpassed all competing devices in terms of quality and speed. Information about this technology currently remains under wraps.

Experiments also revealed that less radiation was required, as the sensor is much more efficient than other types, capable of detecting much smaller amounts of radiation. Together with the fact that the sensitivity is also better in lower energy bands, Applus found the optimum settings well below that of standard film. Finding the right market

A market survey has been conducted to better understand where such a tool could best add value and how that should be done. From interviews with clients, internal managers and field technicians, a picture emerged of several NDT applications where an automated radiography tool could be useful. These are overland transport pipelines, offshore pipelines, thin-walled and exotic materials (for example LNG), bunker facilities and highly critical weld requirements.

Not only are these separate applications, the survey revealed each application has its own specific requirements for an automated system resulting in subtle differences in the development approach.

For reasons of easy integration and familiarity the choice was made to base the design of the frame as much as possible on existing automated ultrasonic testing (AUT) equipment, but with the probes replaced by a radiographic sensor. Applus says that other modifications are required, but generally an operator will feel familiar with the system.

An exception to the above is the design for the smallest bore diameters up to eight inches. For this range the existing AUT frame posed some significant concerns when used as a base for the application. The result was an extensive redesign.

The scanning speed in the current setup is about half the speed of AUT. However, there is potential to go even faster. One way is to simply add a second sensor to the device, effectively making the total cycle time twice as fast. This is currently being designed for the large bore pipelines where the circumference of the weld is much larger.

Another more fundamental approach is to simply increase the sensor area. This is currently being looked at and acceleration of about a factor four seems within grasp.