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Eccentric
A circle not having a geometric centre.
Eccentricity
The variation of the outer diameter of a shaft surface when referenced to the true geometric centreline of the shaft.
Eccentricity of Loading
Distance between the actual line of action of compressive or tensile loads and the line of action that would produce a uniform stress over the cross section of the specimen.
Eccentricity Ratio
The vector difference between the bearing centreline and the average steady-state journal centreline.
ECCM
Abbreviation of Electronic Counter-Countermeasures.
Echo
A delayed return of sound that is perceived by the ear as a discrete sound image.
Echo Canceller
A filter that will remove reflected signals on a transmission line that are caused by impedance mismatches.
Echo Location
Determining the location of a target relative to the sensor face by means of measuring the time it takes for a sound wave to travel to the target and be reflected back to the sensor
Echo Sounding
Measurement of the depth of the ocean by directing a sonic or ultrasonic pressure wave vertically downward and determining the time taken before the echo is received.
Echograms
A record of the very early reverberatory decay of sound in a room.
Eclipse
A chance alignment between the Sun and two other celestial objects within the solar system in which one body blocks the light of the Sun from the other.
ECM
Abbreviation of Electronic Countermeasures.
Ecology
The study of living things in their environment.
Ecosystem
A community of living things together with their environment.
ECU
Abbreviation of Electronic Control Unit.