AMERICAN SOCIETY FOR NONDESTRUCTIVE TESTING (ASNT)
ASNT Q&A Bk C
(1994) Question and Answer Book C:
Ultrasonic Testing Method; (Supplement to
Recommended Practice SNT-TC-1A)
ASNT RP SNT-TC-1A
(2001) Recommended Practice
AMERICAN WELDING SOCIETY (AWS)
AWS D1.1/D1.1M
(2004) Structural Welding Code - Steel
ASTM INTERNATIONAL (ASTM)
ASTM E 165
(2002) Liquid Penetrant Examination
ASTM E 709
(2001) Magnetic Particle Examination
1.2
DEFINITIONS
1.2.1
A Scan
Method of data presentation on a cathode ray tube using rectangular
coordinates in which a horizontal base line indicates elapsed time when
reading from left to right. A vertical deflection in the base line
indicates reflect signal amplitude.
1.2.2
Acoustically Similar Material
Material the same as that to be inspected; or another material proven to
have acoustical velocity within plus or minus 3 percent and an attenuation
within plus or minus 0.009843 dB/mm 0.25 dB/inch of the inspected material
for the inspection frequency and wave mode, using the same mode as that to
be used for inspection.
1.2.3
Amplitude
When referring to an indication in A scan presentation, amplitude is the
vertical height of the indication measured from peak-to-peak for radio
frequency indications and trace-to-peak for video indications.
1.2.4
Attenuation
Dissipation or loss of energy as ultrasonic vibrations travel through the
material. Attenuation is caused almost entirely by scattering of the
ultrasonic vibrations generated by the search unit.
1.2.5
Attenuation-Correction Controls
Circuitry to provide a continuous increase in amplification with respect to
time. This circuitry compensates for the reduction in sensitivity with
depth as a result of sound beam divergence and its attenuation in material.
1.2.6
Back Reflection or End Reflection
Reflection from the opposite side, end, or boundary of the material into
which the ultrasonic energy was introduced.
SECTION 05091A
Page 5
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