ACS UK1401, Руководство по эксплуатации, Страница: 34 / 44

Ultrasonic tester UK1401
Operation Manual
34
ACOUSTIC
CONTROL
SYSTEMS
2
2.3.3 CRACK mode
The screen in the measurement mode of the crack depth is shown in the Figure 35.
In the lower part of the screen the intervals of the ultrasound propagation time are displayed if there is a crack crossing the
propagation path of the signal between the ultrasonic transducers to the right, and to the left if there is no crack in the material.
The mode allows for the determination of the depth of the crack facing the surface. To do it, measure the ultrasound prop-
agation time through the solid material near the crack, and then measure the signal propagation time through the crack. The
instrument will calculate and display the value of the crack depth on the screen.
The instrument determines the DC crack depth (Figure 36) comparing the propagation timet0 of the ultrasonic waves in the
area without crack (path ADB) and t in the area with a crack (path ACB) using the
formula:
Figure 35 Figure 36
DC = AB
•
t 2
-1,
2 t
2
0
where: AB – distance (base of the instrument) between the transmitting
transducer and the receiving transducer.
C
A D B