CONTACT TESTING (UT): Testing with transducer assembly in direct contact with material through a thin layer of
CONTACT TRANSDUCER: A transducer that is coupled to a test surface either directly or through a thin film of
CONTAINER, GAMMA-RAY SOURCE (RT): A device for housing radionuclides and giving a required degree of
protection against radiation. (This may take the form of an exposure device or a storage container.)
CONTAMINATION (PT, MT): Any material in the wet suspension other than the liquid vehicle and the magnetic
material being used. This could be shop dust, lint, soil from improperly cleaned parts, oil, etc.
CONTAMINATION (RT): The presence of unwanted radioactive matter, or the Soiling of object or materials with
CONTINUOUS METHOD (MT): The method in which the inspection medium is applied while the magnetizing
current is on.
CONTINUOUS SPECTRUM (RT): The characteristic radiation pattern that exhibits energies for an unbroken series of
frequencies over a wide range.
CONTINUOUS WAVE (UT): Steady generation of ultrasonic energy; opposite of pulsed.
CONTINUOUS WEDGE (RT): A wedge, the thickness of which varies continuously.
CONTRACTED SWEEP (UT): A contraction of the horizontal sweep line or time axis on the viewing screen of the
ultrasonic instrument. A contraction of this sweep permits viewing defect or back reflection occurring over a greater
length of time.
CONTRAST AGENT (RT): Any suitable substance, solid, liquid, or gas, applied to a material being radiographed, to
enhance its contrast in total or in part.
CONTRAST RATIO (PT, MT): The relative amount of light emitted or reflected as between an indication and its
CONTRAST RATIO (RT): The relative amount of light emitted or reflected as between an indication and its
CONTRAST (MT, PT, RT): The difference in visibility between an indication and the surrounding surface.
CONTRAST, FILM (RT): Change in density that results from a given change in incident radiation. Determined from
the slope of the characteristic curve. See FILM GAMMA.
CONTRAST, RADIOGRAPHIC (RT): The difference in density between an image and its immediate surroundings on
CONTRAST, SUBJECT (RT): The ratio (or logarithm of the ratio) of the radiation intensities transmitted by selected
portions of the specimen.
CONTROL ECHO (UT): Reference signal from constant reflecting surface, such as the back reflection from a smooth,
regular back surface.
CONTROL PANEL (RT): A console or unit that contains the controls necessary to operate a radiation source and any
ancillary equipment used for radiography.