Calibrating To Known Sound Path Values With An Angle Beam Transducer; Locating The Beam Index Point - Olympus EPOCH 650 User Manual

9.8 Calibrating to Known Sound Path Values with an Angle Beam
Transducer
The following sample angle beam calibration procedure is performed using an
Olympus transducer part number A430S-SB with a frequency of 2.25 MHz and an
element size of 15.88 mm × 15.88 mm (0.625 in. × 0.625 in.). The transducer is mounted
on a 45° wedge, part number ABWS-6-45. An Olympus IIW Type I carbon-steel
calibration block, part number TB7541-1, is used.
To calibrate using an angle beam transducer
1. Follow the initial setup procedure outlined in "Basic Setup" on page 143.
2. Connect the transducer to an appropriate cable, and then connect the cable to
either of the conventional transducer connectors at the top of the instrument.
3. Choose Trig > Angle, and then enter the correct refracted angle for the
transducer/wedge combination (45° for this example).
4. Choose Basic > Velocity, and then enter the approximate shear-wave velocity of
the material being inspected (3.240 m/s (0.1280 in./µs) in this example using
carbon steel).
5. Choose Basic > Range, and then enter an appropriate range for the test block
being used (300.00 mm (12.000 in.) in this example using carbon steel).
Review the following procedures:
• "Locating the Beam Index Point" on page 165
• "Verifying the Refracted Angle" on page 167
• "Calibrating for Distance" on page 169
• "Calibrating for Sensitivity" on page 173
9.8.1

Locating the Beam Index Point

The beam index point (BIP) is the point at which the sound leaves the wedge and
enters the material with maximum energy. The following procedure provides a
method to identify the BIP for your probe/wedge.
To locate the BIP
1. Couple the probe to the test block at the 0 mark.
DMTA-10055-01EN, Rev. A, February 2015
Calibration 165