LF ultrasonic penetration tester for materials of high sound attenuation characteristics - uses conical collimating unit of compact porous foam material with through bore in central axis aligned with reception test head

摘要

The appts. for l.f., i.e. from 0.5 to 2 MHZ max., ultrasonic examination of materials which have a pronounced sound attenuation characteristic has a combined carrier assembly (10a, 10b) for the transmitter (13) receiver (14) and testpiece (P) together with the pulsing (11) and evaluation (12) circuitry. The receiver head (14) is equipped with a conical collimator extension (15) formed from a closed-cell foam material with an axial bore of 2 to 3 mm. The collimator (15) is concentric with the head (14) and its larger diameter surrounds the receiver surface to exclude scattered sound waves. USE/ADVANTAGE - Collimator improves resolution. Simple device requiring no change to equipment or method.