Siemens SITRANS LUT400 - Echo Select (2.12.2.)

SITRANS LUT400
220 Operating Instructions, 07/2019, A5E33329501-AC
For best results, calibrate with the level at a known value near Low Calibration Point.
Using Auto Sound Velocity:
Start with a steady distance at a known high distance value (high distance value equates to
a low level value).
1. Review the distance measurement via LUI for approximately 30 seconds to verify
repeatability.
2. Measure the actual distance (for example, with a tape measure).
3. Enter the actual distance, defined in Units (2.1.1.) (Page 168).
Repeat this procedure if the atmosphere type, concentration, or temperature conditions are
different from when the last sound velocity calibration was performed.
Note
In gasses other than air, the temperature variation may not correspond with the speed of
sound variation. Turn off temperature sensor and use a fixed
temperature.
9.2.12.2 Echo Select (2.12.2.)
Algorithm (2.12.2.1.)
Selects the algorithm to be applied to the echo profile to extract the true echo.
Options
TF TRUE FIRST
True First echo
TR TRACKER
TRacker
L LARGEST ECHO
Largest echo
*
BLF BEST F-L
Best of First and Largest echo
ALF AREA LARGEST FIRST
Area, Largest and First
For more details, see Algorithm (Page 292).
Echo Threshold (2.12.2.2.)
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 (3.2.9.2.)
(Page 245) exceeds Echo Threshold (2.12.2.2.), the echo is accepted as a valid echo and is
evaluated.
Values
Range: -20 to 128
Default: 5
Use this feature when an incorrect material level is reported.