Amplitude		Near-surface blind area.
A scan		The act of exposing a material to ultrasound (sending sound waves into it).
Attenuation		Messy zone near probe.
Apparent Attenuation		Real sound loss in material.
B Scan		Cross-section view.
Dead zone		Sound weakening with distance.
C Scan		Wave changes type
critical Angle		Random redirection of sound
Gate		Smallest signal that will produce a visable response "how well the machine can “hear” tiny flaws
Beam Axis		Top-down map view.
Beam Spread		The time sound takes to travel through a part from probe to reflector and back
Diffraction		The ability of UT equipment to separate two discontinuities that are too close
Near Field		Center line of beam.
Immersion Testing		Testing in water.
Far Field		Wave bending at edges.
Insonification		Straight in (90°)
Resolution		Angle where wave changes type.
Normal Incidence		Amplitude vs time/depth (spike chart)
Pulse Length		Uniform beam zone
Sensitivity		Beam widening with depth.
Mode Convertion		How tall the signal spike is on the screen (signal strength)
Scattering		only pay attention to echoes in this area of the timeline
True Attenuation		true attenuation + “extra stuff” that makes signals look weaker.