1. According to the EN, to tune the sensitivity of a setup, AVG diagrams are used, which are found without taking into account damping of elastic waves in a tested specimen. Such is, for example, the AVG diagram for Krautkrämer probes. To test welded joints, the probes are used at frequencies of 2.4 and 5 MHz with the probe angles α = 45°, 60°, and 70°; in the Russian Norms and Rules (NR), the probes are used at frequencies of 1.8, 2.5, and 5 MHz with the angles 40°, 50°, 65°, and 70°