used:
a. The longitudinal waves from the search unit shall be directed
toward the face of the secondary standard closest to the reference hole.
b. The search unit shall be positioned for maximum response. The
amplitude of reflection shall be adjusted to 50 percent full-scale.
The top of that indication on the CRT shall be marked with a wax pencil
or by other means. This establishes the standard reference level. A
point at 80 percent of the standard reference level shall be calculated
and marked. This locates the reject/repair point. The above procedure
shall be repeated for each different surface-to-hole distance to
establish reject/repair lines.
c. With the gain at the same setting and primary standard and search
unit in the bath, a maximized reflection from the 1.52 mm 0.060 inch
reference hole in the primary standard shall be obtained. This gain
setting shall be readjusted to obtain a 50-percent full-scale
reflection. The readjusted setting shall be recorded to provide a
basis for recalibration when the secondary standard is unavailable.
2.9.7
Angle Wave System
The sensitivity level shall be a minimum of a mid-screen height, 50-percent
back reflection, with the transducer placed at the first node position from
a plate edge. No other calibration tests are required unless repair of
discontinuity excavation is accomplished by welding. In that case, when
inspection of the weld repair is required, qualification and calibration of
the shear wave equipment shall be accomplished in accordance with Section
05091A ULTRASONIC INSPECTION OF WELDMENTS.
PART 3
EXECUTION
3.1
PREPARATION OF MATERIALS FOR INSPECTION
The inspection surface shall be clean and free of loose scale, dirt, rust,
grease, oil (other than couplant), and paint. Any roughness on the
inspection surface that could interfere with transmission of the ultrasound
into the material shall be ground smooth enough to obtain a back or end
reflection in excess of 40 percent full-scale. Plates shall be inspected
after final heat treatment or processing. Plate identification removed by
grinding or other means shall be restored after inspection.
3.2
INSPECTION PROCEDURE
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NOTE: The designer shall specify limits closer than
those cited if the application is judged critical.
Inapplicable words, sentences, and paragraphs shall
be deleted when the item mentioned is not to be
furnished under this contract; for example, if clad
plate is not furnished, all reference to clad plate
shall be deleted.
**************************************************************************
Inspection for [laminar types of flaws and] lack of fusion between welded
overlay [or explosion bonded sheet] [and the base metal] shall be made as
detailed below with the search unit coupled to the base plate. The correct
SECTION 05092A
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