This International Standard is applicable to ultrasonic equipment designed for physiotherapy containing an ultrasonic transducer generating continuous or quasi-continuous (e.g. tone burst) wave ultrasound in the frequency range 0,5 MHz to 5 MHz. This standard only relates to ultrasonic physiotherapy equipment employing a single plane non213 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; " 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.