Determination Of Ut Waves Velocity In The Tested Object By Straight Beam Probe - NOVOTEST UD3701 Operation Manual

Operation manual
Ultrasonic Flaw Detector NOVOTEST UD3701
Figure 2.72 – Determination of probe arrow by standard calibration block SO-3

2.5.5 Determination of UT waves velocity in the tested object by straight beam probe

Measurement the velocity of ultrasonic can be performed directly on the tested object or with the
samples made from the same material.
For velocity measurement do the following:
1. Select the place on the product (or on the sample made from the same material) where thickness
measurement of the sample could be measured by using appropriate probe.
2. Mechanically, with required accuracy make measurement of real thickness at the testing point.
3. Set the probe, through couplant, on the sample with known thickness (Figure 2.73).
4. On the device screen multiple reflection echo appears (1H, 2H, 3H etc.).
5. Using gain, make two first signals exceed the standard level (the signal should be within screen
boarders, if necessary, use TVG).
6. Overlap А-gate on the first reflected signal, В-gate – on the second.
7. Check setting «0» of parameter «ANGLE» in parameter group «Probe».
8. Output parameter values «Ya», «Yb» and «Ya-Yb» (for straight beam probe it is possible to use
«La», «Lb» and «La-Lb», beam will be equal to the depth).
9. By changing parameter «VEL» make «Ya-Yb» value equal to measured value H on the sample.
10. By changing parameter «DELAY» in parameter group «Probe» make «Ya» value equal to
measured value H on the sample.
11. Repeat procedure of delay determination 3-5 times to get better accuracy.
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Figure 2.73 – Setting the probe on the sample
Probe arrow