1 research outputs found
Ultrasonic metal sheet thickness measurement without prior wave speed calibration
Conventional ultrasonic mensuration of sample thickness from one side only requires the bulk
wave reverberation time and a calibration speed. This speed changes with temperature, stress,
and microstructure, limiting thickness measurement accuracy. Often, only one side of a
sample is accessible, making in situ calibration impossible. Non-contact ultrasound can
generate multiple shear horizontal guided wave modes on one side of a metal plate. Measuring
propagation times of each mode at different transducer separations, allows sheet thickness to
be calculated to better than 1% accuracy for sheets of at least 1.5 mm thickness, without any
calibration