This International Standard describes methods of calibrating the spatial measurement facilities and point-spread function of ultrasonic imaging equipment in the ultrasonic frequency range 0,5 MHz to 15 MHz. This standard is relevant for ultrasonic scanners based on the pulse-echo principle of the types listed below: − mechanical sector scanners; − electronic phased-array sector scanners; − electronic linear-array scanners; − electronic curved-array sector scanners; − water-bath scanners based on any of the above four scanning mechanisms; − 3D-volume reconstruction systems.