Clef Range (2.4.5.4.); Echo Threshold (2.4.5.3.); Echo Lock (2.4.6.1.); Auto False Echo Suppression (2.4.8.1.) - Siemens SITRANS LR560 Operating Instructions Manual

A.4.3

CLEF RANGE (2.4.5.4.)

Determines the level below which the CLEF algorithm will be used. Above this level, the
Center algorithm is used when Hybrid is selected in POSITION DETECT (2.4.5.2.)
(Page 100). CLEF Range is referenced from FAR RANGE (2.4.2.) (Page 98).
A.4.4

ECHO THRESHOLD (2.4.5.3.)

CONFIDENCE (2.4.7.1.) (Page 103) describes the quality of an echo. Higher values
represent higher quality. Echo Threshold defines the minimum confidence value required for
an echo to be accepted as valid and evaluated.
A.4.5

ECHO LOCK (2.4.6.1.)

If the echo selected by ALGORITHM (2.4.5.1.) (Page 100) is within the Echo Lock window,
the window is centered about the echo, which is used to derive the measurement. In radar
applications, two measurement verification options are used:
Lock Off
SITRANS LR560 responds immediately to a new selected echo (within the restrictions set by
the Maximum Fill / Empty Rate), but measurement reliability is affected.
Material Agitator
A new measurement outside the Echo Lock Window must meet the sampling criteria before
the window will move to include it.
The other available options, Maximum Verification and Total Lock are not recommended for
radar.
A.4.6

AUTO FALSE ECHO SUPPRESSION (2.4.8.1.)

Note
For detailed instructions on using this feature via the handheld programmer, see AFES
WIZARD (1.2.) (Page 88).
Auto False Echo Suppression is designed to learn a specific environment (for example, a
particular vessel with known obstructions), and in conjunction with Auto False Echo
Suppression Range to remove false echoes appearing in front of the material echo.
The material level should be below all known obstructions at the moment when Auto False
Echo Suppression learns the echo profile. Ideally the vessel should be empty or almost
empty, and if an agitator is present, it should be running.
The device learns the echo profile over the whole measurement range and the TVT is
shaped around all echoes present at that moment.
LR560 (PROFIBUS PA)
Operating Instructions, 06/2018, A5E34648471-AE
Technical reference
A.4 Echo processing
169