Figure 11-9 Standard Dac With 3 Db Scanning Gain - Olympus EPOCH 650 User Manual

2. Adjust the gain in either coarse or fine increments, or use the +6 dB and –6 dB
keys (P4 and P5 keys) to increase or decrease scanning gain.
3. Press dB to access the Gain menu.
4. Press Scan dB (P2 key) to toggle between the base (reference) gain and the
adjusted scanning gain.
5. Choose dB > Off to turn scanning gain off completely.
Figure 11-9 on page 235 shows a Standard DAC setup with 3 dB of scanning gain
added.

Figure 11-9 Standard DAC with 3 dB scanning gain

When reference correction is active, the digital comparison between a captured
reflector and the DAC curve is accurate even with the scanning gain applied to the
inspection provided that the gated echo is not saturated. Figure 11-10 on page 236
shows the same setup as above but with Reference Correction active. Notice that the
scanning gain has been removed from the dB-to-curve measurement in location 5. The
instrument compares the echo height to the DAC curve, compensates for the added
scanning gain, and reports the true-amplitude comparison.
DMTA-10055-01EN, Rev. A, February 2015
Software Features and Options 235