Using Focused vs Non-Focused Transducers

Using Focused vs Non-Focused Transducers

When presented with a quote for a new NDE system, let’s say for a tube and pipe application, ask the NDE equipment manufacturer if they plan to use Focused or Non-Focused transducers and why.

There are clear advantages for each type of transducer, but where a Non-Focused transducer can be used on many diameters and wall thicknesses, a Focused transducer is specific to a small range only.
This means that if your NDE system uses focused transducers, you would require many sets to ensure full coverage of all diameters and wall thickness variations. Another drawback for using Focused transducers, is the smaller amount of weld wonder possible before a defect cannot be detected enough to trigger an alarm.

ASTM E273_15 Section 7.1.5 states “The focal length of focused search units shall be at least equal to the radius of the material plus a suitable water path so that initial focus may be on the tube or pipe central axis.”

All these factors and many more play a huge factor in not only the equipment choice, product quality but also the initial cost of the equipment as well as the long-term expenses. This is a very good reason to have the NDE equipment manufacturer mention their compliance with ASTM E273 on the quote for a new NDE system.

Daniel Lucaci

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