Near Field ASME V

Near field — the region of the ultrasonic beam adjacent
to the transducer and having complex beam profiles. Also
known as the Fresnel zone.

Bell Jar Testing ASME V

Bell jar testing — a test used for detecting leakage from
an object completely or partially filled with a tracer gas
and placed in a vacuum chamber or bell jar

Impedance (acoustic) ASME V

Impedance (acoustic) — a mathematical quantity used in
computation of reflection characteristics at boundaries;

Beam Axis ASME V

Beam axis — the acoustic centerline of a search unit’s
beam pattern as defined by the locus of points of maximum
sound pressure in the far field, and its extension
into the near field

Thermography, Infrared ASME V

Thermography, infrared—the process of displaying variations
of apparent temperature (variations of temperature
or emissivity, or both) over the surface of an object or a
scene by measuring variations in infrared radiance

Wobble ASME V

Wobble — in electromagnetic testing, an effect that produces
variations in coil spacing (operational lift-off) due
to lateral motion of the test specimen in passing through
an encircling coil

Processing Speed ASME V

Processing speed—the sustained rate (hits /s), as a function
of the parameter set and number of active channels,
at which AE signals can be continuously processed by a
system without interruption for data transport

Photostimulable Luminescent Phospor ASME V

Photostimulable luminescent phosphor —a phosphor
capable of storing a latent radiological image, which,
upon laser stimulation, will generate luminescence proportional
to the radiation intensity

First Hit Location ASME V

First hit location — a zone location method defined by
which channel among a group of channels first detects
the signal

Blooming ASME V

Blooming — in radiologic real-time imaging, an undesirable
condition exhibited by some image conversion
devices and television pickup tubes brought about by
exceeding the allowable input brightness for the device,
causing the image to go into saturation, producing a fuzzy
image of degraded spatial resolution and grey scale rendition

Backing Space Technique ASME V

Backing space technique — a method of testing for leaks
in which the leak detector is connected to the backing
space to take advantage of the compression of gas that
occurs between the vacuum system and the backing
pump, due to the action of the diffusion pump (or other
type of pump of high speed relative to its backing pump)

Eluant ASME V

Eluant — a liquid used to extract one material from
another, as in chromatography

Spatial Frequency ASME V

Spatial frequency — a measure of detail in terms of
equivalent, uniformly spaced, cyclical patterns. In an
object or image plane, it may be expressed in units of
cycles per millimeter (cy /mm) or line pairs per millimeter
(lp /mm). In an imaging system, it may be expressed in
units of cycles per milliradian (cy /mrad) or line pairs per
milliradian (lp /mrad).

Imaging Line Scanner ASME V

Imaging line scanner — an apparatus that scans in a
single dimension and is moved perpendicular to the scan
direction to produce a two-dimensional thermogram of
a scene

Overload Recovery Time ASME V

Overload recovery time—an interval of nonlinear operation
of an instrument caused by a signal with amplitude
in excess of the instrument’s linear operating range

Object Plane Resolution ASME V

Object plane resolution — the dimension in the object
plane that corresponds to the product of a system’s instantaneous
field-of-view and a specified distance from the
system to the object

Audible Leak Indicator ASME V

Audible leak indicator — an accessory to a leak detector
which converts the output signal to an audible note whose
frequency is a function of the leakage rate

Overwashing ASME V

Overwashing — too long or too vigorous washing, or
both, which results in removal of penetrants from some
discontinuities

Resonance Method ASME V

Resonance method — a technique in which continuous
ultrasonic waves are varied in frequency to identify resonant
characteristics in order to discriminate some property
of a part such as thickness, stiffness, or bond integrity

Radiological Examination ASME V

Radiological examination—the use of penetrating ionizing
radiation to display images for the detection of discontinuities
or to help ensure integrity of the part