Glossary - Siemens Sitrans LR400 Instruction Manual

Glossary

accuracy: degree of conformity of a measure to a standard or a true value.
ADC: analog to digital converter
ambient temperature: the temperature of the surrounding air that comes in contact with the
enclosure of the device.
antenna offset: propagation time of the signal in the sensor, expressed as a distance.
Auto False-Echo Suppression: a technique used to adjust the level of a TVT curve to avoid the
reading of false echoes. (See TVT.)
Auto False-Echo Suppression Distance: defines the endpoint of the 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
sound beam.
beam spreading: the divergence of a beam as it travels through a medium.
blanking: a blind zone extending away from the reference point plus any additional shield
length.The instrument is programmed to ignore this zone.
confidence: describes the quality of an echo. Higher values represent higher quality.
Confidence threshold defines the minimum value.
current limit: The maximum possible value of the output signal in fault-free operation in mA.
The value of the fail signal may be above the current limit with 24 mA.
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.
dead band (blanking): a blind zone extending away from the reference point plus any
additional shield length.The instrument is programmed to ignore this zone.
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
1.
Many conductive liquids/electrolytes exhibit dielectric properties; the relative
dielectric constant of water is 80.
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