2.4.5.4.
Notes:
• CLEF Range is referenced from Far Range.
• The value for CLEF Range must include the difference between Far
The CLEF (Constrained Leading Edge Fit) algorithm is used mainly to allow
correct level reporting for low dK materials which may otherwise cause an
incorrect reading in an empty or almost empty vessel.
It is used from Far Range up to the level defined by CLEF Range (see
illustration below). Above that point the Center algorithm is used. For more
detail see CLEF Range (2.4.5.4.) on page 141.
Values
Related
parameters
CLEF Range
2.4.5.5.
The point on the primary echo on which the measured value is based.
Values
Use this feature if the reported material level fluctuates slightly, due to a
variable rise in the leading edge of the true echo on the Echo Profile.
Enter the value (in percent of echo height) to ensure the Echo Lock
Window intersects the Echo Profile at the sharpest rising portion of the
Echo Profile representing the true echo. This value is preset to 70%.
7ML19985LY01
CLEF Range
Range and Low Calibration Point, plus any level above the Low
Calibration Point to be managed by the CLEF algorithm.
Range: 0 to 45 m (40 m device)
Default: 0.0 m
Position Detect (2.4.5.2.)
Far Range (2.4.2.)
Echo Marker
Range: 5 to 95%
Default: 70%
SITRANS LR560 (FF) – INSTRUCTION MANUAL
0 to 105 m (100 m device)
Low Calibration
Point
sensor
reference
point
Far
Range
Page 97