Olympus EPOCH 6LT, User Interface Manual

Page: 207 / 232

DMTA-10084-01EN, Rev. 2, November 2018
Software Features and Options 197
(precision and scanning), as each mode uses a separate set of calibration data. Also,
the calibration must be performed using an Olympus thickness gage dual transducer.
See “Calibration” on page 89 for instructions on performing a thickness calibration.
11.7.3.2 Basic Measurement Adjustments
Common basic adjustments in both the scanning mode and the precision mode
include rectification and manual gain adjustment. The precision mode also
incorporates extended blanking control.
• Rectification
All rectification views are available in the corrosion module, including full wave
and RF (the most common selections).
• Gain Adjustment
Gain is adjusted manually in scanning mode. Automatic gain control (AGC) is the
default (and recommended) in precision mode, but some applications may
require manual gain adjustment while in precision mode to achieve optimal
results. Often this requirement is related to transducer sensitivity. If the
transducer sensitivity is low, the default initial gain for the transducer may not be
sufficient to allow measurements while AGC is on. If the transducer is overly
sensitive, or the test material is highly transmissive, the default initial gain may be
too great and result in amplified noise or cross talk, causing incorrect
measurements.
• Extended Blanking Control
Based on the material and (or) the transducer, the corrosion module detection
algorithm may incorrectly trigger measurements from a signal before the first
back wall. This signal can be caused by surface conditions, transducer cross talk,
or other factors. If a measurement is incorrectly triggered (see Figure 11-37 on
page 198), you can adjust the start position of the measurement window.