(12) Turn the transducer in the transducer guide hole to make sure the notch signal is at a maximum
amplitude. Move the guide above reference notch 2, position Z one more time to make sure the
signal is at a maximum height. Adjust the instrument gain controls to get the notch 2 signal at
80% of full screen height (see Figure 7).
(13) Examine all noise signals to make sure the signal-to-noise ratio is larger than 3:1. If the
signal-to-noise ratio is less than 3:1, try a different transducer or a higher frequency transducer.
NOTE: Make sure the initial pulse is not more than 20% of full screen width. If necessary, adjust
the instrument controls or use a different transducer.
(14) Put couplant on the fuse pin to be examined. Then put the transducer guide with the transducer
on the end of the fuse pin.
(15) Set the back wall signal to 100% of full screen height.
(16) Add 4 dB. During the inspection, if there are crack signals, the crack signals will be above 40% of
full screen height.
B. Calibration for Fuse Pin 65B94182-8 only
NOTE: The transducer is angled in transducer positioner NDT4123P to make a shear wave for this
inspection.
(1) Get reference standard NDT4123 and transducer positioner NDT4123P as shown in Table 2.
(2) Connect the transducer to the instrument and do the initial adjustments of the instrument.
NOTE: Do not use reject unless the instrument has certified linear reject. Do not use more than
10% reject.
(3) Set the instrument frequency to 10 MHz. See Paragraph 2.A.(1).
(4) Put couplant at position 1 on the reference standard. Put the transducer at this position. See
Figure 6.
(5) Adjust the instrument controls to get the first back surface signal at 50% of full screen width and
the second back surface signal at 100% of full screen width. The instrument is now calibrated for
a 5.0 inch (127 mm) instrument screen range. See Figure 6.
(6) Put couplant in the transducer guide hole. Put the transducer into the transducer guide.
(7) Put couplant on the reference standard at position X shown in Figure 8. Put the transducer at this
position. The back surface signal must occur near 98% of full screen width.
NOTE: A signal can occur at 90% of full screen width that is caused by an internal reflection.
(8) Move the transducer guide above reference notch 1 at position Y (see Figure 8). The screen
location for the reference notch 1 signal must be at 45% of full screen width as shown in Figure 8.
(9) Move the transducer guide above reference notch 2 at position Z (see Figure 8). The screen
location for the reference notch 2 signal must be at 72% of full screen width as shown in Figure 8.
(10) Turn the transducer in the transducer guide hole to make sure the notch signal is at a maximum
amplitude. Move the transducer guide above reference notch 2, position Z one more time to make
sure the signal is at a maximum height. Adjust the instrument gain controls to get the notch 2
signal at 80% of full screen height. See Figure 8.
747
NONDESTRUCTIVE TEST MANUAL
PART 4 54-30-10
Page 3
Nov 15/2015D6-7170
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
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