INDICATION (PT): The visible evidence of penetrant which has come out of a discontinuity, indicating to the
inspector that some sort of surface opening is present.
INDICATION (UT): The signal displayed on the ultrasonic equipment.
INDIVIDUAL MONITORING DEVICES: Devices designed to be worn by a single individual for assessment of dose
equivalents. Although they may include film badges, thermoluminescent dosimeters (TLDs), pocket ionization
chambers and personal air sampling devices, their use within the Army is usually limited to TLDs.
INDUCED CURRENT MAGNETIZATION (MT): A special technique used to establish a circular field for the
detection of circumferential discontinuities in ring-shaped parts without making direct contact with the surface of the
part. Sometimes referenced as Induced Field.
INDUCED RADIOACTIVITY: Radioactivity that is created by bombarding a substance with neutrons in a reactor or
with charged particles produced by particle accelerators.
INDUCED RADIOACTIVITY (RT): Radioactivity resulting from irradiation of matter.
INDUCTANCE: A property of a circuit that opposes any change in the existing current. Inductance is present only
when the current is changing. A coil is a source of inductance.
INDUCTION: Magnetic induction is the magnetism induced in a ferromagnetic body by some outside magnetizing
INDUCTION HARDENING: Quench hardening in which the heat is generated by electrical induction.
INDUCTIVE REACTANCE: This is the opposition, independent of resistance, of a coil to the flow of an alternating
INDUSTRIAL RADIOLOGY (RT): That branch of radiology covering industrial applications of ionizing radiation.
INGATE: Same as GATE.
INGOT: A casting suitable for working or remelting.
INHERENT DEFECTS: Defects introduced into steel at the time it originally solidifies from the molten state.
INHERENT FILTRATION (RT): The filtration exhibited by the walls and other materials of a radiation source through
which the radiation must pass before it is utilized. Inherent filtration affects the spectral distribution of the radiation,
and thus, the quality of the final radiograph.
INHERENT UNSHARPNESS (RT): See UNSHARPNESS.
INHIBITOR: A substance that retards some specific chemical reaction such as rusting.
INITIAL PULSE (UT): Electrical pulse generated by the ultrasonic instrument; used to excite a search unit in order to
produce ultrasonic energy. Sometimes called the main bang.
IN-MOTION RADIOGRAPHY: A method in which either the object being radiographed or the source of radiation is in
motion during the exposure.
IRRELEVANT INDICATION: See GHOST.
INSPECTION: Process of examining for possible defects or for deviation from established standards.