User's Manual

7ML19985LY01 SITRANS LR560 (FF) – INSTRUCTION MANUAL Page 149
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Glossary
Glossary
accuracy: degree of conformity of a measure to a standard or a true value.
agitator: mechanical apparatus for mixing or aerating. A device for creating turbulence.
algorithm: a prescribed set of well-defined rules or processes for the solution of a problem in a
finite number of steps.
ambient temperature: the temperature of the surrounding air that comes in contact with the
enclosure of the device.
antenna: an aerial which sends out and receives a signal in a specific direction. There are four
basic types of antenna in radar level measurement, horn, parabolic, rod, and waveguide.
Auto False-Echo Suppression: a technique used to adjust the level of a custom TVT curve to
avoid the reading of false echoes. (See TVT.)
Auto False-Echo Suppression Range: defines the endpoint of the Learned TVT distance. (See
TVT.) This is used in conjunction with auto false echo suppression.
beam angle: the angle diametrically subtended by the one-half power limits (-3 dB) of the
microwave beam.
blanking: a blind zone extending away from the reference point plus any additional shield
length.The instrument is programmed to ignore this zone.
capacitance: the property of a system of conductors and dielectrics that permits the storage of
electricity when potential differences exist between the conductors. Its value is
expressed as the ratio of a quantity of electricity to a potential difference, and the unit is a
Farad.
confidence: see Echo Confidence
damping: term applied to the performance of an instrument to denote the manner in which the
measurement settles to its steady indication after a change in the value of the level.
dB (decibel): a unit used to measure the amplitude of signals.
derating: to decrease a rating suitable for normal conditions according to guidelines specified
for different conditions.
dielectric: a nonconductor of direct electric current.
dielectric constant (DK): the ability of a dielectric to store electrical potential energy under the
influence of an electric field. Also known as Relative Permittivity. An increase in the
dielectric constant is directly proportional to an increase in signal amplitude. The value is
usually given relative to a vacuum /dry air: the dielectric constant of air is 1.
1)
echo: a signal that has been reflected with sufficient magnitude and delay to be perceived in
some manner as a signal distinct from that directly transmitted. Echoes are frequently
measured in decibels relative to the directly transmitted signal.