In DGS diagrams of Russian documents (e.g., [5]), the damping coefficient is introduced depending on the frequency of the probe used and the material of the tested object. This fact eliminates the requirement in document [1] that “damping should be measured at different places of the tested object and where significant changes are found corrections should be made.” Application of AVG diagrams with a certain damping is forbidden during ultrasonic testing of austenitic welded joints and cast articles because of an abrupt change in damping at different places of the tested objects. In these cases, either reference blocks with reflectors are used or radiographic testing is used instead of ultrasonic testing. Use of the reference blocks V1 and V2 for tuning with AVG diagrams [2] and CB-2 (calibration block 2) and CB-3 for tuning by DGS diagrams is not essential because introducing a correction (the difference in amplitudes of echo signals in the specimens) makes it possible to pass from one type of specimens to another. If CB-2 and CB-3 specimens are used, differences in the wave velocities and damping in the specimens are more significant. This difference leads to great errors during estimation of the equivalent area (diameter) of the found discontinuities, which is unacceptable. The method of calculation of DGS diagrams developed by V.A. Voronkov