Specifies a standard means and format for the reporting of the acoustic output of medical diagnostic ultrasonic equipment. The numerical values for reporting purposes represent the average values for the maximum output conditions for a given discrete- or combined-operating mode and are derived from measurements made in water. Intensity parameters are specified in this standard, but these are regarded as derived quantities that are meaningful only under certain assumptions related to the ultrasonic field being measured. This International Standard is applicable to medical diagnostic ultrasonic equipment. - It provides a set of traceable acoustic parameters describing the acoustic fields. - It defines a standard means and format for the reporting of the acoustic output information. - It also describes a reduced dataset recommended for equipment generating low acoustic output levels. This second edition cancels and replaces the first edition published in 1992. This edition constitutes a minor revision. The changes with respect to the previous edition are listed below: - maintenance on this standard and the referenced standards IEC 61161 and IEC 62127-1. - a clause on compliance has been added.