Figure 11-42 Corrosion Module Echo Measurement - Olympus EPOCH 650 User Manual

DMTA-10055-01EN, Rev. A, February 2015
2. Use the knob or arrow keys to change the Status parameter (P7) to On.
3. The measurement box automatically changes to measure Gate 2 – Gate 1.
4. Choose the Rcvr menu item (group 1/4).
5. Use the knob or arrow keys to change the Rect parameter (P1) to RF so you can
view the positive and negative amplitude values.
As a result of the roof angle of dual transducers, often a shear wave is also produced
in the inspection material when using a dual probe. Shear wave velocity is slower
than longitudinal wave, so the shear component is displayed after the first backwall
echo. If the shear wave component is significant enough to cross the measurement
threshold, it can trigger a false measurement from the gate 2 region in Echo-to-Echo
mode. This causes a measurement error (see Figure 11-43 on page 285).
284 Chapter 11

Figure 11-42 Corrosion Module echo measurement