Calibrating With A Straight Beam Transducer; Dmta-10055-01En, Rev. A, February - Olympus EPOCH 650 User Manual

DMTA-10055-01EN, Rev. A, February 2015

angle. The shallow reflector depth allows for zero offset calibration, and the deep
reflector depth allows for velocity calibration.
9.3

Calibrating with a Straight Beam Transducer

The sample straight beam calibration described below is performed using an
Olympus transducer part number A109S-RM, with a frequency of 5.0 MHz and an
element diameter of 13 mm (0.50 in.).
The calibration requires a test block with two known thicknesses made from the
material to be measured. Ideally, the two thicknesses should represent thicknesses
that are both below and above the expected thickness of the material being inspected.
For this example, Olympus standard 5-step steel test block (P/N: 2214E) is used. The
steps measure 0.100 in., 0.200 in., 0.300 in., 0.400 in., and 0.500 in.
If the EPOCH 650 is set to work in metric units, the calibration process is exactly the
same, except that the entries are in millimeters rather than inches.
To calibrate using a straight-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 transducer connectors at the top of the instrument.
3. Choose Auto Cal > Type = Thickness.
4. Couple the transducer to the thin calibration block step. For this example, the
transducer is coupled to the 0.200 in. step.
Depending on the frequency of the contact transducer being used, it might be
impossible to obtain a proper reading on very thin material.
5. Use the G1Start button (P5 key) to position gate 1 so that the first back-wall echo
from the known thickness step exceeds the gate threshold.
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