P4G-4 Airborne Ultrasonic Confocal Instrument for Parametric Imaging of Complex Samples

A 680 kHz confocal airborne ultrasonic instrument was built for quantitative material characterization based on parametric imaging. This instrument allows characterization of fragile or moist sensitive samples. Few such instruments are commercially available. The instrument performs simultaneous attenuation and time-of-flight measurements in linear reflection and transmission modes. Sample surface topography is measured in reflection mode and local sample thickness is calculated using the inter-transducer distance. Results for a Pinus Sylvestris test sample are presented. The speed of sound, attenuation, and modulus of elasticity can be mapped locally (local density was measured with X-ray in transmission mode). No repeatable nonlinear sample characteristics were achieved for this sample.