TM 1-1520-264-23
a.
Clean ultrasonic transducer with a low-lint cloth, MIL-C-85043 or equivalent Clean all contact surfaces when
using a wedge or delay block. Apply couplant to these contact surfaces and carefully tighten the assembly prior
to test.
NOTE
Scratches or similar surface blemishes remaining on the transducer or wedge may give false indications.
b.
Use prescribed or equivalent couplant and in sufficient quantity to achieve proper coupling. The use of lubricants
containing graphite, silicones, and glycerines is prohibited.
c.
Apply adequate pressure to keep transducer in contact with part.
d.
Use moderate speed for transducer search pattern. If transducer movement is too fast, a flaw could be passed
over without a proper indication.
1.4.13 Acceptance/Rejection Criteria.
CAUTION
Misinterpretation of indications can result in rejectable parts being accepted and
acceptable parts being rejected. Only NDI personnel trained and qualified in accordance
with applicable military standards and technical manuals shall perform and interpret
nondestructive inspections.
Nondestructive inspection procedures in this manual have been selected to enhance the safety of the aircraft and
personnel. Inspection procedures (including primary and backup) have been outlined to enable NDI personnel to perform
a reliable inspection of parts with respect to their design, composition, and accessibility. In the event that a final
interpretation of an indication cannot be made, assistance from the next higher maintenance level shall be requested.
1.4.14 Equipment Used for NDI. Refer to Table 1-7 for a summary of equipment used for NDI in this manual.
Equivalent equipment may be used unless specified otherwise in the inspection procedures.
1.4.15 Materials Used for NDI. Refer to Table 1-8 for a summary of materials used for NDI in this manual. Common
commercial grade materials (cheesecloth, paper, etc.) are not listed. Equivalent materials may be used unless specified
otherwise in inspection procedures.
1.4.16 Post Cleaning and Restoration of Part or Area After NDI. Upon completion of the NDI test and prior to restoration
of protective finishes, it is necessary to clean off residual inspection materials from the part. This cleaning will vary
based upon test method, contaminant, and subsequent processing of the part. In many instances, methods used for
precleaning are acceptable for post cleaning. Refer to Preparation of Part or Area for NDI, paragraph 1.4.4.
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