Fig. 4From: Automated Surface Wave Measurements for Evaluating the Depth of Surface-Breaking Cracks in ConcreteIsometric view of a concrete beam (specimen 2), and data acquisition and signal generation systems for surface wave measurement using surface-mount sensors (a), sectional view of the specimen 2 (B-B′), and (c) sectional view of the specimen 2 (C–C′).Back to article page