User's Manual

Page 92 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE03
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Parameters
2.8.4.3. Echo Threshold
Sets the minimum echo confidence that the echo must meet in order to
prevent a Loss of Echo condition and the expiration of the Fail-safe (LOE)
timer. When Confidence (2.8.6.1.) exceeds Echo Threshold (2.8.4.3.), the
echo is accepted as a valid echo and is evaluated.
Use this feature when an incorrect material level is reported.
2.8.4.4. CLEF Range
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.
CLEF range is the level below which the CLEF algorithm is used when
Hybrid is selected in Position Detect (2.8.4.2.). Above that point the Center
algorithm is used. For more detail see Position Detect (2.8.4.2.)
on page
127
).
In applications with low dK materials we recommend setting CLEF Range
to 0.5 m (1.64 ft) and Position Detect (2.8.4.2.) to Hybrid.
2.8.5. Sampling
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.
2.8.5.1. Echo Lock
Selects the measurement verification process.
For radar applications, Material Agitator is the most often-used setting, to
avoid agitator blade detection.
Values
Range: 0 to 99
Default: 5
Related
Parameters
Timer (2.5.2.)
Values
Range: 0 to 20 m (0 to 65.6 ft)
Default: 0.00 m
Related
parameters
Position Detect (2.8.4.2.)
Note: Ensure the agitator is always running while SITRANS LR250
is monitoring the vessel, to avoid stationary blade detection.
Options
Lock Off
Maximum Verification (not recommended for radar)
*
Material Agitator
Total Lock (not recommended for radar)
Related
parameters
Fill Rate (2.4.2.)
Empty rate (2.4.3.)
Sampling Up (2.8.5.2.)
Sampling Down (2.8.5.3.)