Open Access

The areas of application of air-coupled ultrasonic testing (ACUT) can be very diverse and often differ greatly from the areas of application of classic ultrasonic testing. In fact, ACUT is an independent method that often overlaps with X-ray or thermography or enables tests that cannot yet be reliably performed non-destructively. Although air-coupled ultrasonic testing is not a new technology, it remains a rarely used method compared to other NDT methods. This is not least due to the lack of standards, specialised books and training opportunities for interested inspectors and inspection supervisors. This creates a barrier to entry for many areas of application, which prevents more frequent use. For these reasons, experts from research institutes and industry have decided to set up an "Air-Coupled Ultrasonic Testing" (ACUT) sub-committee as part of the DGZfP's Ultrasonic Testing Technical Committee to work on these topics. It was decided to draw up a guideline to make it easier for interested users to get started with ACUT and to provide assistance with the specification and implementation of such tests. This document is the result of this co-operation.