IEC 61689:2013 is applicable to ultrasonic equipment designed for physiotherapy containing an ultrasonic transducer generating continuous or quasi-continuous wave ultrasound in the frequency range 0,5 MHz to 5 MHz. This standard only relates to ultrasonic physiotherapy equipment employing a single plane non-focusing circular transducer per treatment head, producing static beams perpendicular to the face of the treatment head. This standard specifies: - methods of measurement and characterization of the output of ultrasonic physiotherapy equipment based on reference testing methods; - characteristics to be specified by manufacturers of ultrasonic physiotherapy equipment based on reference testing methods; - guidelines for safety of the ultrasonic field generated by ultrasonic physiotherapy equipment; - methods of measurement and characterization of the output of ultrasonic physiotherapy equipment based on routine testing methods; - and acceptance criteria for aspects of the output of ultrasonic physiotherapy equipment based on routine testing methods. Therapeutic value and methods of use of ultrasonic physiotherapy equipment are not covered by the scope of this standard. This third edition cancels and replaces the second edition published in 2007. It constitutes a technical revision which includes the following significant technical changes with respect to the previous edition: - restriction introduced of 0,2 W/cm2 effective intensity during hydrophone measurements for treatment heads with ka≤20, to limit the likelihood of cavitation; - change in the factor Fac, to determine the effective radiating area, from 1,354 to 1,333; - and change to SI units for terms and definitions. This publication is to be read in conjunction with IEC 60601-2-5:2009.