Operating Manual

Important Notice
Page iv Guide to Ultrasonic Inspection of Fasteners
Testing Limitations
Information collected as a result of ultrasonic testing rep-
resents only the condition of test-piece material that is
exposed to the sound beam. Operators must exercise
great caution in making inferences about the test mate-
rial not directly exposed to the instrument’s sound beam.
When a less-then-complete inspection is to be per-
formed, the operator must be shown the specific areas
to inspect. Inferences about the condition of areas not
inspected, based on data from evaluated areas, should
only be attempted by personnel fully trained in appli-
cable techniques of statistical analysis.
Sound beams reflect from the first interior surface en-
countered. Operators must take steps to ensure that the
entire thickness of the test material is being examined.
Calibrating the instrument/transducer combination is
particularly important when the test piece is being ultra-
sonically tested for the first time or in any case where
the history of the test piece is unknown.
Transducer Selection
The transducer used in testing must be in good condi-
tion without noticeable wear of its contact surface. Badly
worn transducers will have a reduced effective measur-
ing range. The temperature of the material to be tested
must be within the transducer’s temperature range. If
the transducer shows any signs of wear it should be re-
placed.