Baker Hughes 022-508-909, Operating Manual

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CL 5 4-39
maximum thickness observed during the evaluation
period is displayed. Its corresponding A-Scan can
also be displayed by pressing . At this point the
screen is frozen. Recouple the probe to reactivate the
display screen (Section 4.3).

Note:
During the placement of a very sensitive probe on the
part surface, excess couplant may cause erroneous
results. To eliminate the effect of excessive couplant,
couple the probe firmly to the part, then press un-
der the ASCAN function, then press under HOME.
This restarts the scanning session while the probe is
properly in contact with the part.
DIFF / RR%
(Differential / Rate-of-Reduction) – The
currently measured and user-inputted nominal
thickness appear along the top of the display while
the difference between these two values (measu-
red minus nominal values expressed in percentage
and dimensional terms) appears in the middle of the
display. Note that the displayed differences can have
positive or negative values (Section 4.4).
THK + A-SCAN
(Thickness and A-Scan, available
only with A-Scan) – An A-Scan appears in the center
portion of the display and the thickness value
is shown in the display’s upper right-hand corner
(Section 4.5).
VELOCITY
(Material Velocity, available only with
velocity option) – The material velocity value appears
as large digits in the center of the display. This
velocity calculation requires an accurate NOMINAL
THICKNESS value which can be inputted by the user or
by using the connected digital caliper. Note that no
live A-Scan is displayed but an A-Scan snapshot of
the triggering echo can be accessed (Section 4.6).
QUALITY
(Quality View Mode, available only with
Data
Recorder option) – The measurement bar graphic
appears on the top of the screen together with the
measurement location, name, minimum specified
value, the target value and the upper specified value.
When the transducer is coupled to a part, the
thickness value is displayed. The measurement bar
graphic shows where the thickness value is in the
range, with relation to the lower and upper specified
limits.
Measuring Thickness
Normal Measurement Mode