PULSE (UT): A series of vibrations or oscillations having a brief duration.
PULSE-ECHO METHOD (UT): An inspection method in which the presence and position of a discontinuity is
indicated by the echo amplitude and time position; also designates a method of inspecting bonded honeycomb structures
by monitoring the echoes from the far side of the core.
PULSE LENGTH (UT): A measure of the duration of a pulse, expressed in time or number of cycles.
PULSE REPETITION RATE (UT): See FREQUENCY, PULSE REPETITION.
PULSE TUNING (UT): Control, on some instruments, used to optimize the response of the search unit and cable.
PYROMETER: Any device used for determining temperatures over a wide range, including extremely high
QUALITY CONTROL INDICATOR (RT): See PENETRAMETER.
QUALITY FACTOR (RT): The linear-energy-transfer-dependent factor by which absorbed doses are to be multiplied to
obtain, for radiation protection purposes, a quantity (i.e., dose equivalent) that expresses on a common scale for all
ionizing radiation the irradiation incurred by exposed persons. The quality factor weights the absorbed dose for the
biological effectiveness of the particular type of radiation producing the absorbed dose. Symbol: Q.
QUALITY LEVEL (RT): See RADIOGRAPHIC QUALITY LEVEL.
QUALITY OF RADIATION (RT): The quality of a radiation determines its degree of penetration, and is related to the
energy of the radiation.
QUANTUM: If the magnitude of a quantity is always an integral multiple of a definite unit, then that unit is called the
quantum of the quantity. The photon is a quantum of the electromagnetic field and the meson is considered to be the
quantum of the nuclear field.
QUANTUM (RT): A discrete amount of radiation energy. The quantum energy is E=hu, where u is the frequency of
the radiation and h is Planks constant.
QUENCH AGING: Aging induced by rapid cooling after Solution Heat Treatment.
QUENCH ANNEALING: Annealing an austenitic ferrous alloy by Solution Heat Treatment.
QUENCH CRACKS: See CRACKS, QUENCHING.
QUENCH HARDENING: Hardening a ferrous alloy by austenitizing and then cooling rapidly enough so that some or
all of the austenite transforms to martensite. The austenitizing temperature for hypoeutectoid steels is usually above
Ac3 and for hypereutectoid steels usually between Acl and Accm.
QUENCHING: Rapid cooling. When applicable, the following more specific terms should be used: direct quenching,
fog quenching, hot quenching, interrupted quenching, selective quenching, spray quenching, and time quenching.
QUICK-BREAK: Sometimes called FAST BREAK. The sudden breaking of a direct current causes a transient
current to be induced in the part by the rapid collapse of the magnetic field. In magnetic particle testing, fast breaking
of the magnetizing current is used to generate a transient current in a part which is favorable for finding transverse
defects at the ends of longitudinally magnetized bars. Such defects are often concealed by the strong polarity at the bar