Annealed Copper Standard) - Conductivity as a percentage of pure
- A coalescence of meal beyond the root of the weld.
A process to produce an image of an opaque object on film for study.
- The test method in which the test object and the transducer are submerged
in a liquid (usually water) that acts as the coupling medium. The transducer
is not usually in contact with the test object.
Transducers - A device that focuses sound energy
on an object in a water environment. Immersion transducers do not come in
direct contact with the object.
Ultrasonic Testing - A NDT that is completed with squirters where the
sound travels through a jet of water or by taking the transducer and test
object and immersing them in a tank of water.
- The total opposition in an electrical circuit to flow of alternating
- Represents the combination of those electrical properties that affect the
flow of current through the circuit.
Acoustic - See acoustic impedance.
Matching - The process of matching the system impedance to the cable impedance,
otherwise error-producing reflections are created.
Method - Eddy current method, which monitors the change in prove
impedance; both phase and amplitude.
Plane - The plane formed by the resistance component
and the reactance component.
- Elements or compounds whose presence in a material is undesired.
Photon - Absorption of x-rays occurs when the x-ray
photon is absorbed resulting in the ejection of electrons from the outer shell
of the atom. That photon is called the incident photon.
- Nonmetallic particles, usually compounds in a metal matrix. Usually considered
undesirable, though in some cases, such as in free machining metals, inclusions
may be deliberately introduced to improve machinability.
Scattering - The process when the incident x-ray
photon ejects a electron from an atom and an x-ray photon of lower energy
is scattered from the atom. (Also known
as Compton Scattering
Fusion - Welding fusion which is less than compete. Failure of weld
metal to fuse completely with the base metal or preceding bead.
Joint Penetration (Lack of Fusion)
- Welding fusion that fails to penetrate to complete thickness of the materials
being joined. Appears as elongated darkened lines of varying length and width
which may occur in any part of the welding groove.
Penetration - Welding root penetration which is less than complete
or failure of a root pass and backing pass to fuse with each other.
Thinking - The process of being able to think on
your own, with out someone else guiding you.
- In nondestructive testing, the response from or the evidence of a discontinuity
in material condition or structure.
Passing an alternating current through a conductor will set up a fluctuating
magnetic field. If a second conductor in the form of a closed loop is placed
in this field, the action of the fluctuating field moving across the conductor
will set up a second alternating current of the same frequency. This is an
Radioactivity - Radioactivity that is created by bombarding a substance
with neutrons in a reactor or with charged particles produced by particle
- Ratio of the total magnetic flux-linkage in a coil to the current flowing
through the coil.
- The process of generating current in a conductor by placing the conductor
in a changing magnetic field.
Hardening - A method of locally heating the surface of a steel or
cast iron part through the use of alternating electric current. It is usually
necessary to rapidly cool, or quench, the heated volume to form martensite,
the desired hard microstructure.
Reactance - The opposition to a change in alternating current flow.
- A coil.
- The property of matter that causes it to resist
any change in its motion.
Defects - Discontinuities which are normal in the material at the
time it originally solidifies from the molten state.
- The pulse applied to excite the transducer. It is the first indication on
the screen if the sweep is undelayed. Also called the main bang. May refer
to an electrical pulse or an acoustic pulse.
- Irradiation with sound.
- Materials that do not have any free electrons. Because of this fact,
they do not tend to share their electrons very easily and do not make good
conductors of electrical currents.
- Materials that resist the flow of electrons.
- A layer of material placed in contact with the film to increase the effect
of the radiation, thus shortening the exposure.
- The amount of energy a sound has over an area. The same sound is more
intense if you hear it in a smaller area. In general, sounds with a higher
intensity are louder.
- The boundary between two contacting parts or regions or parts.
- Triggering the sweep and auxiliary functions from an interface echo occurring
after the initial pulse. Also called IF synchronization.
- When two or more sound waves from different sources are present at the
same time, they interact with each other to produce a new wave. The new wave
is the sum of all the different waves. Wave interaction is called interference.
- Corrosion occurring preferentially at grain boundaries.
Fracture - Brittle fracture of a metal in which the fracture is between
the grains, or crystals, that form the metal. Contrasted to transgranular
- A device for precluding access to an area of radiation hazard either by
preventing entry or by automatically removing the hazard.
Probe (coil) - A probe for testing tube (or holes) from the inside.
The coil(s) is circumferentially wound on a bobbin.
- The determination of the source and relevancy of an ultrasonic indication.
- Inverse Square
Law - The equation stating some A = 1 /
- A charged atom or molecularly bound group of atoms; sometimes also a free
electron or other charged subatomic particle.
- A positive ion and a negative ion or electron having charges of the same
magnitude, and formed from a neutral atom or molecule by the action of radiation
or by any other agency that supplies energy.
- This process of radiation absorption.
Chamber - An instrument that detects and measures ionizing radiation
by observing the electrical current created when radiation ionizes gas in
the chamber, making it a conductor of electricity.
Radiation - Radiation of sufficiently high energy
to knock electrons out of the orbits of atoms and molecules, often creating
more ionizing radiation and adversely affecting living tissues. Biologically
significant radiation is an ionizing dose of radiation above 155 ev which
may have carcinogenic, mutagenic, or other health effects in humans.
192 - A radioactive isotope of the element Iridium which has a half-life
of 75 days. It is used extensively as a source of gamma radiation.
- Exposure to radiation, as in a nuclear reactor.
- One or two or more nuclides having measurable time intervals in different
- Isotope -
One of two or more atoms of the same element that have the same number of
protons in their nucleus but different numbers of neutrons. Most elements
have more than one naturally occurring isotope.
- A condition in which significant medium properties (velocity, for example)
are the same in all directions.