RECIPROCITY CALIBRATION OF ACOUSTIC-EMISSION TRANSDUCERS IN RAYLEIGH-WAVE AND LONGITUDINAL-WAVE SOUND FIELDS

A new system was developed for the reciprocity calibration of acoustic emission transducers in Rayleigh-wave and longitudinal-wave sound fie lds. In order to reduce interference from spurious waves due to reflec tions and mode conversions, a large cylindrical block of forged steel was prepared for the transfer medium, and direct and spurious waves we re discriminated between on the basis of their arrival times. Frequenc y characteristics of velocity sensitivity to both the Rayleigh wave an d longitudinal wave were determined in the range of 50 kHz-1 MHz by me ans of electrical measurements without the use of mechanical sound sou rces or reference transducers. (C) 1997 Acoustical Society of America.