Читать книгу Monument Future - Siegfried Siegesmund - Страница 261

There were 77 micro cracks observed on the surface of the statue and 15 of them were chosen for testing with either mode A or B, depending on the position of the crack.

The ultrasonic device used was a Proceq PunditLab+, with the precision of 0.1 µs on wavetime reading and the probes were Proceq 40 17-B 54 KHz conical probes (Fig. 5), with the contact area of diameter 4 mm, that ensures the precision of the contact points and the accurcy of testing results. Fig. 6 shows examples of cracks detected. Table 2 shows the calculated depth results of fifteen cracks and the depth ranged from 0 to 68 mm.

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Figure 4: Principle of ultrasonic CT.