Siemens SITRANS L Operating Instructions Manual page 134

Parameter reference
CLEF Range (2.5.7.4.)
Note
CLEF Range is referenced from Low Calibration Point (process empty level).
The CLEF 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 Low Calibration Point (process empty level ) 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 (Page 237).
Values
Related parameters
①
②
③
In applications with low dK materials we recommend setting CLEF Range to 0.5 m (1.64 ft)
and Position Detect (2.5.7.2.) to Hybrid.
Sampling (2.5.8.)
Provides a method of checking the reliability of a new echo before accepting it as the valid
reading, based on numbers of samples above or below the currently selected echo.
Echo Lock (2.5.8.1.)
Note
Ensure the agitator is always running while SITRANS LR250 is monitoring the vessel, to avoid
stationary blade detection.
Selects the measurement verification process. See Echo Lock (2.5.8.1.) for more details.
Options
134
Range: 0 to 20 m (0 to 65.6 ft)
Default: 0.0 m
Position Detect (2.5.7.2.)
CLEF Range
Sensor reference point
Low calibration point (process empty level)
Lock Off (no verification)
Maximum Verification
* Material Agitator
SITRANS LR250 with FOUNDATION FIELDBUS
Operating Instructions, 09/2021, A5E32221411-AH