T.O. 33B-1-1
Glossary 15
COMPTON ABSORPTION (COMPTON EFFECT) (RT): The reduction of the energy of an incident photon by its
interaction with an electron. Part of the photon energy is transferred to the electron (Compton electron or recoil
electron) and part is redirected as a photon of reduced energy.
COMPTON EFFECT (RT): The glancing collision of an X-ray or gamma ray with an electron resulting in a gain of
energy for the electron.
COMPTON SCATTERING (RT): A process in which a photon transfers a portion of its energy to an orbital electron in
matter and a lower energy photon is scattered at an angle to the original photon path.
COMPUTED TOMOGRAPHY (RT): A method by which a radiograph of a predetermined interior plane of a thick
material is obtained through the use of a computer. The images resulting from a series of exposures at different angles
are stored and reconstructed into a single image by the computer.
CONCAVE: Curved or rounded and hollow as the outer boundary of a spherical or circular form viewed from within;
opposite of convex.
CONCENTRATE (MT): A term used colloquially to designate the dry magnetic materials used to prepare a
suspension. Also called Dry Concentrate.
CONCENTRATION TEST (MT): The method used to determine the quantity of magnetic material in the suspension at
any given time. Also known as settling test.
CONDENSER IONIZATION CHAMBER (RT): An ionization chamber which, having been charged to a certain
potential, can be irradiated and subsequently attached to an electrometer to measure the residual charge, whereby the
exposure is determined.
CONDUCTIVITY: This is the inverse of resistance, and refers to the ability of a conductor to carry current.
CONDUCTIVITY REFERENCE STANDARD (ET): Sections of metallic materials with accurately measured electrical
conductivity values in percent IACS. These standards are used to calibrate conductivity measuring eddy current
instruments.
CONE (RT): A lead diaphragm or cone placed on the tube head to limit the X-ray beam to a volume defined by a cone.
CONSTANT-POTENTIAL CIRCUIT: A circuit, which is so, arranged to apply and maintain a substantially constant
potential across an X-ray tube.
CONSTANT VOLTAGE (CONSTANT POTENTIAL) (RT): A unidirectional voltage of essentially constant
magnitude.
CONSTRAINT: Any restriction that occurs to the transverse contraction normally associated with a longitudinal
tension, and that hence causes a secondary tension in the transverse direction.
CONTACT HEAD (MT): Electrode assembly used to clamp and support a part to facilitate passage of electrical current
through the part for circular magnetization.
CONTACT METHOD (UT): The inspection method in which the search unit face makes direct contact with the test
part and ultrasonic energy is transmitted through a thin film of couplant.
CONTACT PADS (MT): Replaceable metal pads, usually copper braid, placed on the contact heads to give good
electrical contact, thereby reducing the possibility of damage to the part by arcing or burning.
