Siemens sitrans PROBE LU User Manual

7ML19985JB02 SITRANS Probe LU (PROFIBUS PA) – INSTRUCTION MANUAL Page 115
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Glossary
Glossary
acoustic noise: any undesired audible sound.
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.
attenuation: a term used to denote a decrease in signal magnitude in transmission from one
point to another. Attenuation may be expressed as a scalar ratio of the input magnitude to
the output magnitude or in decibels.
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: the distance in front of the transducer face where level measurement is not possible.
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: describes the quality of an echo. Higher values represent higher quality.
Confidence threshold defines the minimum value.
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.
Note: Parameter names are capitalized.

Siemens sitrans PROBE LU Specifications

General

Measuring Principle	Ultrasonic
Communication	HART
Output	4 to 20 mA
Power Supply	12 to 30 V DC
Process Temperature	-40 to 80 °C
Enclosure Rating	IP68
Material	PVDF
Ambient Temperature	-40 to 70 °C
Measurement Range	0.25 to 12 m (0.8 to 39 ft)