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2.9
Calibrating the Instrument / Probe
Combination
The phased-array calibration process requires the use
of a calibration standard, of proper material type, with
two known reflectors. Completing the process requires
adjustment of the PROBE DELAY and VELOCITY values
to match the instrument/probe/test piece combination in
use. Before launching the calibration process, complete
all applicable tasks described in Chapters 2 and 3
including:
•
Inputting the Probe and Wedge characteristics
•
Define the scan
•
Input Material Type
•
Input Ultrasonic settings
•
Configure the RESULTS displayed to include SBA,
SA, and BEAM Angle.
•
Position the A and B Gates to capture the two
known reflectors on the calibration standard (cap-
ture the deeper reflector with the B-Gate). Set Gate
Detection Logic to POSITIVE. Be sure IF GATE
LOGIC is set to OFF.
•
Move the BEAM CURSOR to select the "nominal"
effective angle of the probe wedge, which is the
refraction angle in the test object based on the given
wedge angle (Snell's Law).
To launch the calibration process:
Step 1: Activate the CAL Submenu (Located in the PART
MENU) by pressing
down the left side of the display.
Step 2: Couple the probe to the calibration standard so
that the first reflector is captured in A-Gate and the second
(deeper) reflector is captured by the B-Gate. Press
next to VELOCITY and adjust the value until the displayed
SBA value matches the depth of the calibration standard's
known reflector.
Step 3: Couple the probe to the calibration standard so
that the first reflector is captured in A-Gate. Press
to PROBE DELAY and adjust the value until the displayed
SA value matches the depth of the calibration standard's
known reflector.
The material velocity and probe delay are now adjusted
to match the instrument/probe/test piece combination.
PHASOR XS Operating Manual
below it. Selections will appear
2. Setting Up for Phased Array Measurement
2.9.1 Performing a Quick Calibration
Using the optional calibration block purchased with your
instrument (or one you've fabricated), a quick calibration
procedure (matched to a designated sector-scan applica-
tion) can be performed as follows:
Setup Procedure
Step 1: Press
view.
Step 2: Use the BEAM CURSOR to select the desired
reference A-Scan (such as 45 degrees). Beam cursor is
controlled via the CAL submenu in the PART menu.
Step 3: Adjust the LEG setting (HOME menu) to move
the displayed cal-block reflectors to screen positions
corresponding to 1 and 4 inches (25 and 100 mm for the
equivalent EN calibration block).
Step 4: Display and position the A-Gate (using the GA-
TEMODE and GATE POS submenus located in the UT
menu) to detect the first cal-block reflector. Be sure the
IF GATE LOGIC is set to OFF.
Step 5: Display and position the B-Gate (using the GA-
TEMODE and GATE POS submenus located in the UT
menu) to detect the second cal-block reflector.
Step 6: Adjust gate detection mode to PEAK or FLANK
as required by your calibration procedure.
Step 7: Display SA and SBA measurements (accessed
via the RESULTS1 submenu located in the DISPLAY
menu).
Step 8: Adjust the probe position to maximize the echo
amplitude.
Step 9: Adjust instrument gain to move the largest dis-
played echo to just below 100% FSH.
next
to display the A-Scan-plus-Sector Scan
Page 31
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