Siemens Sitrans LR400 Instruction Manual page 45

First, when the level is low, dip the vessel to determine the exact distance to the
material. Then, set Auto False-Echo Suppression Distance (4.2.3.9) to 2 meters
shorter than this dipped distance.
This function works best when the vessel is nearly empty. For best results, do
Note:
not record or learn when the vessel is completely empty.
Value
If all signals fall below this defined threshold, then the failsafe timer is initiated.
4.2.3.9 Auto False-Echo Suppression Distance (F = 2/3 tank height)
Defines the end point of the auto false echo suppression distance.
Value
7ML19985FH06 SITRANS LR400 (7ML5421) – INSTRUCTION MANUAL
Off
Record
Use
variable to maximum range
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