Statistical error analysis of time and polarization resolvedultrasonic measurements

摘要

The time and polarization resolved ultrasonic technique which wenpreviously developed has been demonstrated to simultaneously providenmeasurements of the wave velocity in the coupling liquid, and the leakynsurface wave and leaky longitudinal wave velocities in solid samples. Tondocument the measurement precision associated with this technique, anstatistical method is employed for the data fit and error analysis. Withnthe help of statistical analysis, the simple ray model used to determinenwave velocities in this technique is first confirmed by theoretical datanwhich are predicted by the Green's function. Error analysis is thennapplied to the experimental data. The results show that this techniquenhas a relative expanded uncertainty (equal to twice the standardndeviation) of 0.03% for the wave velocity in water, and an uncertaintynless than 0.2% and 2%, respectively, for the leaky surface and leakynlongitudinal wave velocities in a crown glass sample. The uncertainty innthe repeatability for leaky surface wave measurements is observed to benmuch less than the expanded uncertainty of a single measurement set.nThis methodology also has been applied to a set of steel samples. Thenresults allow that the expanded uncertainty for leaky surface wavenvelocities is less than 0.07%, enabling a correlation of the measurednvelocities with specific sample heat treatments