POWDER, DRY (MT): Finely divided ferromagnetic particles suitably selected and prepared for magnetic particle
PRECIPITATE (MT): The separating of the magnetic particles from the liquid vehicle. Used primarily for checking
concentration of magnetic particles in the vehicle.
PRECIPITATION HARDENING: The process by which a metal is hardened by the formation of small particles of
secondary composition from a solid solution. This process is usually performed at an elevated temperature considerably
below the temperature of solution heat treating.
PRECIPITATION HEAT TREATMENT: Artificial aging in which a constituent precipitates from a supersaturated
PRE-CLEANING: The cleaning of a part before testing so that it is free from all foreign material (paint, grease, oil,
rust, scale, layout dye, wax crayon markings, etc.) which may cover a surface discontinuity and thereby inhibit the
entrance of the penetrant liquid, or absorb the penetrant and render an irrelevant indication.
PRESENTATION: The method used to show ultrasonic wave information. May include A, B, or C scans displayed
either on various types of recorders or cathode ray instrumentations.
PRESERVATIVE, DEVELOPER (RT): A constituent (e.g., sodium sulfate) that minimizes the exhaustion of a
developer caused by aerial oxidation, and serves to remove oxidation products which might retard development or
PRESSURE MARK (RT): An effect produced by pressure on a film which after developing results in areas of either
increased or decreased density. The crescent-shaped pressure mark due to severe local bending of a film is often called
a crimp mark.
PRIMARY MAGNETIC FIELD (ET): In eddy current inspection, the field produced by the test coil or coils as
differentiated from the magnetic field produced by the eddy current or the resultant field.
PRIMARY RADIATION (RT): Radiation coming directly from the source of radiation that has undergone no physical
process changing its character.
PROBE (ET, MT, UT): An assembly containing a small coil or coils designed for eddy current inspection of small
areas immediately adjacent to the coil and an electromagnet producing magnetic fields for magnetic inspection. The
unit has two jointed laminated pole pieces permitting adjustment to varying surfaces configuration. Also the device
contains a microphone used with an ultrasonic leak detector to receive ultrasonic energy resulting from leakage. See
PROBE WOBBLE (ET): The change in angular orientation between a surface probe and the inspection surface. Probe
wobble results in lift-off variations.
PROCESS ANNEALING: In the sheet and wire industries, heating a ferrous alloy to a temperature close to, but below,
the lower limit of the transformation range and then cooling, in order to soften the alloy for further cold working.
PROCESS ATTAINMENT (ABILITY): The ultimate ability of a process to find a defect of minute size at the current
state-of-the-art, usually defined as the ability to detect defects as small ... See SENSITIVITY.
PROCESS CAPABILITY: The ability of a process to repeatedly find a defect under the influence of normal day-to-day
variations of process, people, materials, environment and other influences normally tied to a confidence level.