Prior to fabrication, the block material shall be completely examined with
a straight beam search unit. Areas that contain an indication exceeding
the remaining back-wall reflection shall be excluded from the beam
paths required to reach the various calibration reflectors.
4.7.4 Heat Treatment
The calibration block shall receive at least the minimum tempering
treatment required by the material specification for the type and grade.
If the calibration block contains welds other than cladding, and the
component weld at the time of the testing has been heat treated, the
block shall receive the same heat treatment.