Siemens SITRANS LUT400 Operating Instructions Manual page 190

2.12.1.6. Auto Sound Velocity
Note: Auto Sound Velocity supports adjustments to distance value only.
Adjusts the speed of sound and changes the distance measurement
calculations. Defined in 2.1.1.Units
Values
Condition for use of this feature:
•
•
•
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
2. Measure the actual distance (for example, with a tape measure).
3. Enter the actual distance, defined in
Repeat this procedure if the atmosphere type, concentration, or
temperature conditions are different from when the last sound velocity
calibration was performed.
Note:
correspond with the speed of sound variation. Turn off temperature
sensor and use a fixed temperature.
2.12.2. Echo Select
2.12.2.1. Algorithm
Selects the algorithm to be applied to the echo profile to extract the true
echo.
Options
For more details, see Algorithm on page 259.
Page 182 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS
Range: 0.000 to 60.000
The acoustic beam atmosphere is other than air
The acoustic beam atmosphere temperature is unknown
The Reading accuracy is acceptable at higher material levels only
to verify repeatability.
In gasses other than air, the temperature variation may not
TF
TR
L
* BLF
ALF
.
2. 1 . 1 .Units
TRUE FIRST
TRACKER
LARGEST ECHO
BEST F-L
AREA LARGEST FIRST
.
True First echo
TRacker
Largest echo
Best of First and Largest
echo
Area, Largest and First
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