Figure 11-10 Dac With 3 Db Scan Gain - Reference Correction Active; Curve Adjustment Gain (Dac Gain Or Tcg Gain) - Olympus EPOCH 650 User Manual

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

Figure 11-10 DAC with 3 dB scan gain - reference correction active

11.2.3.2

Curve Adjustment Gain (DAC Gain or TCG Gain)

The overall gain level of the entire DAC curve and TCG line setup can be adjusted
higher or lower from the Reference Gain. Most inspection codes do not permit
reflectors to be sized below 20 % FSH. Therefore, to inspect beyond a certain
depth/sound path time within a part, it is necessary to raise the gain of both the live
A-scan and the DAC curve to continue the inspection. This is accomplished on the
EPOCH 650 using the curve gain (DAC curve adjustment gain).
To adjust the curve gain
1. Choose DAC/TCG > Gain Step, and then use the Up and Down arrow keys or the
adjustment knob to choose the desired increment of the gain adjustment.
2. Press DAC Gain (P1 key), and then adjust the curve gain by the selected
increment either positive or negative.
Figure 11-11 on page 237 shows a DAC setup with DAC gain in use to provide
accurate echo amplitude measurement by placing the echo close to 80 % FSH.
236 Chapter 11