This standard specifies: - the essential non-thermal output characteristics of ultrasonic surgical units; - methods of measurement ot these output characteristics; - those characteristics which should be declared by the manufacturers of such equipment. This standard is applicable to equipment which meets the requirements of a, b and c below: a) ultrasonic surgical systems operating in the frequency range 20 kHz to 60 kHz; and b) ultrasonic surgical systems, whose use is the fragmentation or cutting of human tissue, whether or not those effects are delivered in conjunction with tissue removal or coagulation; and c) ultrasonic surgical systems, in which an acoustic wave is conducted by means of a specifically designed wave guide to deliver energy to the surgical site.