This part of IEC 61391 specifies terms and methods for measuring the maximal depth of penetration and the local dynamic range of real-time ultrasound B-MODE scanners. Belonging to the types of converters used with these scanners are: - mechanical probes; - electronic phased arrays; - linear arrays; - curved arrays; - two-dimensional arrays; - three-dimensional scan probes on the basis of a combination of the aforementioned types. All scanners dealt with are based on pulse-echo technology. The test methodology applies to converters operating in a frequency range from 1 MHz to 15 MHz, both in fundamental frequency and in harmonic frequency modes (harmonic modes) by which up to 15 MHz are detected. The testing at harmonic frequencies above 15 MHz is not dealt with in this standard. The responsible Committee is Joint Subcommittee GUK 821.3 "Medizinische Ultraschallgeräte" ("Medical ultrasonic equipment") of the DKE (German Commission for Electrical, Electronic and Informational Technologies) at DIN and VDE.