Term Categories: Glossary

A fluid (usually a liquid but can be a gas) which possesses unique properties that render it highly capable of entering small openings, a characteristic which makes this fluid especially suitable for use in the detection of surface discontinuities which may be present.

Unit of electrical resistivity; the resistivity of 1 m3 of material, which has a resistance of 1 ohm when electrical current flows between opposite faces; the standard unit of measurement for resistivity.

The unit of electrical resistance through which 1 amp of current will flow when the potential difference is 1 V.

Any unwanted signal; a disturbance that is not part of signal from specified and unknown sources.

Repetitive echoes from the far boundary of the test object.

Observing the change in a NDE or geophysical measurement with time

A seismic/radar term whose general meaning is the correction of the recorded image for the effects of reflector dip. A very typical result of migration is the removal of hyperbolic features on the record resulting from reflections from objects and other discontinuities and more accurate description of the reflectors.

A unit of electrical conductance that is the reciprocal of ohm

Locating information from NDE or geophysical measurements in space (as opposed to time, which is monitoring). The results are usually summarized as maps.

A device for measuring the magnetic field. Variations in the field strength may indicate changes in magnetic properties of the tested material or presence of ferrous metals.