GE Phasor CV, Operating Manual

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8. Working in TOP View (Optional Feature)
PHASOR XS Operating Manual Page 103
With the Interface GATE display switched to ON, A- and
B-Gate’s starting positions are automatically based on
the occurrence of an IF-Gate triggering. This occurrence
becomes the zero point from which A- and B-Gate starting
values are measured (
Figure 8-6 ).
For example if A-Gate’s START is set to 1 inch, the gate
will start the equivalent of 1 inch from the IF-Gate trigger
for each BEAM. If the probe-to-part distance changes, the
A-Gate START point will automatically adjust accordingly.
In addition, this adjustment will take place independently
for each beam. This positions the A-Gate, in this case,
at a fixed distance from the sound entry surface in the
test piece, insuring the desired material depth is being
evaluated.
IF loss can occur from loss of coupling, or when the dis-
tance from the probe to the part exceeds an acceptable
limit. Limits are established to insure the phased array
delay law calculations remain valid for the beam. The
variations described effect this Phased Array delay law
calculation, for both angle steering and focal depth. Delay
law calculations are based on an assumed “Z” distance
(Section 2.3.3).
NOTE: When operating in TOP View mode with the
IF-Gate turned on, a loss of the interface signal will
prevent the the offending beam from recording data
to the TOP View. Instead, the operator is alerted to
the condition with the application of a special IF LOSS
color to the TOP VIEW Image.
NOTE: Turing ON the IF-Gate also impacts control of
the DISPLAY START function. Refer to Section 2.6.3
to define the display’s starting point with and without
the IF Gate on.
Additionally, there is a DISPLAY START control related to
the IF GATE. The choices are IF, IP and MATERIAL.
FIGURE 8-6—