Olympus EPOCH 650 User Manual page 339

Term
Rectification
Reference echo
Reference gain
(reference level)
Reference line
Reference reflector
Refraction, angle of
Reject (control)
Resolution
Scanning gain
Second critical angle
Table 32 Glossary (continued)
Receiver function that selects display of waveforms as an
RF signal with both positive and negative deflections, a
full wave rectified signal in which all deflections are
displayed as positive, or half wave negative and positive
in which only one side of the RF signal is displayed as a
positive deflection.
The echo from a specified reference reflector.
A gain level established by a test procedure, commonly by
setting a reference reflector echo to a specified height.
A designated percentage of total screen height at which
reference echoes and indication echoes are compared.
A reflector of known size and geometry at a known
distance, such as a flat bottom hole.
The angle with respect to perpendicular of the sound
beam in the test material, generated by refraction from the
angle of incidence in the wedge.
Also known as suppression, this limits the input
sensitivity of the amplifier in the receiver to display only
indications greater than a selected height. It is used to
reduce or eliminate "grass" or scattering noise from the
display.
The ability of the test system (instrument and transducer)
to distinguish between two reflectors at slightly different
depths, or within a given distance of the surface of the test
piece.
The amount of gain above the reference level added per
procedure to optimize visibility of indications.
In angle beam or immersion testing, the minimum
incident angle in the wedge or water path at which the
refracted shear wave disappears from the test piece.
DMTA-10055-01EN, Rev. A, February 2015
Definition
Glossary 327