Sonatest Ltd. (Milton Keynes, Bucks, U.K.) has developed the Dryscan 410D digital flaw detector. It uses the Shadow Technique to nondestructively test composites, hybrids and honeycomb structures in aerospace and marine applications. Specially designed transducers eliminate the need for a coupling medium. No material surface preparation is required, and many of the geometric considerations that are applied to conventional ultrasonic detection methods reportedly can be ignored. The flaw detector has a tunable filter that can be adjusted, allowing the user to select the best signal response for the test material. The resulting reduction in noise increases the instrument’s sensitivity, enabling the testing of attenuative materials.