Measurement of nonlinearity parameter (β) of water using commercial immersion transducers

The determination of absolute nonlinearity parameter (β) for water using a finite-amplitude method is described here. Measurements were carried out using commercial immersion transducers, thus making this technique field adaptable. Calibration of immersion transducers is based on a simplified version of the calibration technique proposed by Dace et al. With corrections for diffraction and attenuation, the nonlinearity parameter calculated for water is in good agreement with literature, providing a validation for the methods developed. The current study is aimed at progressing towards measuring the nonlinearity parameter of immersed solids using commercially available ultrasonic equipment. This work is supported by the Industry/University Cooperative Research Center members of the Center for Nondestructive Evaluation at Iowa State University.