Selecting Beam-Groups Of Interest During The Tcg Recording Process; Applying Incremental Gain To Beam Groups During The Recording Process; Manually Imputing Tcg Points - GE Phasor CV Operating Manual

3. Operating in Phased Array Mode
Step 4: Move the probe so that additional segments on
the display's left side indicate the presence of the first
reflector. Again, display segments move to the right from
their baseline position by an amount that's proportion-
ate to the maximum A-Scan amplitude (in A Gate) they
acquire. All segments must indicate the presence of the
reflector (by moving to the right of their baseline position)
and no segment may indicate an amplitude greater than
100% full-screen-height. Ideally, with sufficient movement
of the probe, display segments will represent somewhat
consistent amplitudes.
Step 5: After each display segment sufficiently indicates
the reflector's presence, press
NOTE: Pressing and holding (for three seconds)
that appears next to the <RECORDING> Function
deletes the currently active TCG point.
Step 6: Continue to move the probe to observe additional
reference points and repeat Steps 2 and 3 until TCG points
for all reflectors are recorded (up to a maximum of 15).
Then press (two times) next to FINISH. At this time
the TCG Curve is generated and active. The effects of
TCG can be turned on or off (TCG MODE) without deleting
the reference points. However, the curve must be deleted
before a new TCG can be recorded.
Step 7: Access the TCG EDIT Submenu to add points
to or otherwise adjust the existing TCG Curve after it has
been finished. To delete curve, press and hold key.
NOTE: When a TCG reference point is stored, two
measurement result boxes will be automatically set
(if not already configured) to display PPA and P%A
values. These result selections will remain locked
until TCG reference recording is completed (Step 6
above).
NOTE: TCG reference points and status (OFF or TCG)
will be stored with data set. When recalled, curve status
will be the same as when it was stored. For example, if
TCG is active when a data set is stored, it will be active
when that data set is recalled.
3.6.2 Selecting Beam-Groups of Interest
During the TCG Recording Process
During the recording process, the gain applied to one or
more beam-group segment can be reduced to eliminate
the effect of an undesired reflector (such as a geometric
feature that is detected by these specific segments) on
the recording of a TCG point. To select a region of interest
during the TCG-point recording process:
Step 1: Press next to the BEAM GROUP Function
(identified in Figure 3-9).
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to record POINT 1.
Step 2: Identify the first beam group(s) for which you want
to define a TCG point.
Step 3: Adjust gain as required and record the TCG refer-
ence data (by pressing
indicated group(s). The instrument will NOT proceed to
the next TCG point at this time.
Step 4: As prompted, continue to identify beam groups
and apply suitable gain to those groups, recording the
beam groups as described in Step 4.
Step 5: When data has been recorded for all beam
groups, the TCG recording process will automatically
proceed to the next TCG point.
3.6.3 Applying Incremental Gain to Beam
Groups During the Recording
Process
The cycle gain control feature allows an incremental
amount of gain (measured in dB) to be added to each
beam. Prior to beginning the TCG-point recording pro-
cess, press next to the CYC GAIN CNTL Function
then turn the Function Knob to incrementally apply the
indicated amount of gain to each beam.
For example: applying an additional 2 dB to three beams
in this manner means that 2 dB is added to the first beam,
4 dB added to the second, and 6 dB added to the third.
After the TCG-point recording process has begun, cycle
gain can still be added by pressing the same key, identi-
fied in Figure 3-9 (WARNING: pressing this key twice will
finish the TCG process).

3.6.4 Manually Imputing TCG Points

TCG reference points may also be manually input us-
ing the TCG EDIT Submenu, as shown in
When manually inputting TCG points, the material-depth
measurement (called POINT POS.) and additional gain
to be applied at that A-Scan depth, is entered for up to
15 points.
next to RECORDING) for the
Figure
PHASOR XS Operating Manual
3-10.