Siemens SITRANS L Series Operating Instructions Manual page 65

Setup with the integrated HMI
7.8.1 Signal
Echo selection
Sets the algorithm (applied to the echo profile) for determining the useful echo.
If the selection " First large echo" is activated, pressing the button " ↓" selects
the response threshold in dB.
Setting
SIGNAL
Filtering
The reform echo is used to smooth the echo profile in bulk solids applications.
Fragmented echoes are merged. Use this function when monitoring bulk solids when
the level indication fluctuates slightly although the material surface remains calm.
Enter the amount for the required smoothing of the echo profile.
The transmitter damping value sets the damping (filtering) of the transmitter raw
value to smooth sudden process value fluctuations.
Note
The process value adjusted as primary variable (PV) for the application, is damped by
using the values in the parameters " Damping value" and " Transmitter damping
value". All other process values (which are not preset or selected as main PV) are
only damped by the value in parameter " Transmitter damping value".
Setting
SIGNAL
TVT configuration
Defines the threshold curve below which all echoes are ignored.
The Hover Level sets the offset of the TVT (Time varying threshold) curve with
respect to the basic noise of the echo profile. Specified in dB with respect to the basic
noise and peak value of the largest echo.
Automatic false echo suppression (AFES) is used for false echo suppression in vessels
with known installations. When AFES is activated, the effective range is selected as
distance in mm by pushing the button " ↓".
A determined TVT curve replaces the preset TVT curve in the set effective range.
Procedure for optimum results with auto false echo suppression:
1.
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Selection
ECHO SELECT
Selection
FILTERING
If possible, set the automatic false echo suppression during commissioning by
executing the " Auto false echo suppression wizard".
Selection
ALGORITHM ON
ALGORITHM OFF
Selection
REFORM ECHO
Description
Selection first large echo
activated
Value of the response
threshold
Selection first large echo
deactivated
Description
Echo merging enabled
SITRANS LR150
Operating Instructions, 08/2020, A5E50352155