Olympus EPOCH 6LT, User Interface Manual

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DMTA-10084-01EN, Rev. 2, November 2018
Software Features and Options 153
You can only select unlicensed options. All licensed options are shaded and cannot be
selected.
3. Select an Unlicensed option and note the 16-character software serial number for
your instrument that appears in the Gage S/N parameter.
4. Contact Olympus to purchase the software option, using the software serial
number to identify your instrument.
5. After Olympus provides you with the remote activation code, open the Software
Options setup page.
6. Press the Tab key to move to the Enter Option Key box, and then press the Enter
key to display the virtual keypad.
7. Using the virtual keypad, adjustment knob, and Enter key, enter the activation
code in the
Enter Option Key box.
8. Press the Tab key to select Activate .
9. Press the Enter key to activate the option and return to the live A-scan display.
11.3 Dynamic DAC/TCG
A distance-amplitude correction (DAC) curve is used to plot amplitude variations of
signals from reflectors of the same size, but at different distances from the transducer.
Normally, these reflectors produce echoes of varying amplitude due to material
attenuation and beam spreading as the sound beam travels through the part. The
purpose of the DAC curve is to graphically compensate for material attenuation, near-
field effects, beam spreading, and surface roughness.
After plotting a DAC curve, reflectors of the same size as those used for creation of the
curve produce echoes that peak along the curve despite their different locations
within the test piece. Similarly, reflectors that are smaller than those used to create the
curve fall below the level, while larger reflectors exceed the curve level.
When a DAC curve is created in the EPOCH 6LT ultrasonic flaw detector, the
instrument also creates a time-corrected gain (TCG) setup. TCG is used to compensate
for the same factors as DAC, but the presentation is different. Instead of drawing a
curve across the display that follows the reference-reflector peaks downward as
sound is attenuated, the TCG setup amplifies the gain as a function of time (distance)
to bring the reference reflectors to the same screen height (80 % FSH).
NOTE