- A data presentation method applied to pulse echo techniques. It produces
a two-dimensional view of a cross-sectional plane through the test object.
The horizontal sweep is proportional to the distance along the test object
and the vertical sweep is proportional to depth, showing the front and back
surfaces and discontinuities between.
The signal received from the far boundary or back surface of a test object.
- The visual, radiographic or electronic response against which an indication
from a discontinuity must be viewed.
fluorescence - Fluorescent residues observed over the general surface
of the part during fluorescent penetrant inspection.
Noise - The extraneous signals caused by random signal sources within
or exterior to the ultrasonic testing system, including the test material.
Sometimes called grass or hash.
Radiation - The radiation of man's natural environment, consisting
of that which comes from cosmic rays, the naturally radioactive elements of
the earth and the impact of the cumulative deposition from stratospheric fallout
and nuclear accidents such as Chernobyl. Term may also mean radiation extraneous
to an experiment.
Scatter - Scattered signals that are directed back to the transmitter/receiver.
- An intermediate transformation product from austenite in the heat treatment
of steel. Bainite can somewhat resemble pearlite or martensite, depending
on the transformation temperature.
Concept - An idea or model used to facilitate the explanation of
radiation exposure permitted in a lifetime.
- The reference line in a measurement by triangulation.
(I.e. The horizontal trace across the A-scan display. It represents time and
is generally related to material distance or thickness.)
- Macroscopic lines on a fatigue fracture that show the location of the tip
of the fatigue crack at some point in time. Must not be confused with striations,
which are extremely small and are formed in a different way.
- Beam Alignment
Measurements - Measurements that provide data on the degree of alignment between the sound
beam axis and the transducer housing. This information is particularly useful
in applications that require a high degree of certainty regarding beam positioning
with respect to a mechanical reference surface
Exit Point - See probe index.
- Beam Profiles
- A measurement of the intensity of the beam across
its width (or profile). It provides valuable information about transducer
sound field characteristics. Transverse beam profiles are created by scanning
the transducer across a target (usually either a steel ball or rod) at a given
distance from the transducer face and are used to determine focal spot size
and beam symmetry. Axial beam profiles are created by recording the pulse-echo
amplitude of the sound field as a function of distance from the transducer
face and provide data on depth of field and focal length.
- The divergence of the sound beam as it travels through a medium. Specifically,
the solid angle that contains the main lobe of the beam in the far field.
- Beer's Law
-the ability of a penetrant to yield an indication depends primarily
on its ability to fluoresce as a very thin film. The performance of penetrants
based on the physical constraints of the dyes can be predicted using Beer's
Law equation. This equation does not hold true when very thin layers are involved
but works well to establish general relationships between variables.
Henri - The discoverer of naturally occurring radioactive uranium in 1896.
He showed how these particles differed from the recently discovered x-ray
radiation by showing that they could be deflected by an electric or magnetic
- A particle accelerator that is used to accelerate electrons (beta particles)
and collide them with a target to produce high energy radiation.
- Beta Radiation
- A high speed electron, small in mass, moderate penetrating abilities (e.g.
unable to penetrate more than a few millimeters of biological tissue).
- See ultraviolet light.
- Bottom Echo
- See back reflection.
- The edge, end or face of a finite medium.
- Reflection of an ultrasonic wave from an interface.
- A German term that means "braking rays." It is an important
phenomenon in the generation of X-rays. In this process, a high speed electron
traveling in a material is slowed or completely stopped by the forces of any
atom it encounters.
- Brittle Rupture
- A material failure mechanism that results with little or no plastic
(permanent) deformation prior to fracture.
- Having a relatively wide frequency band width. Used to describe pulses that
display a wide frequency spectrum and receivers capable of amplifying them.
Opposite of narrow banded or tuned.
- See water column.