User's Manual

Parameter reference
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 01/2014, A5E32221386-AB
117
To set Auto False Echo Suppression via the handheld programmer:
Options
OFF
Default TVT will be used.
*
ON
’Learned’ TVT will be used.
LEARN
’Learn’ the TVT.
1. Determine Auto False Echo Suppression Range. Measure the actual distance from the
sensor reference point to the material surface using a rope or tape measure.
2. Subtract 0.5 m (20") from this distance, and use the resulting value.
3. Go to
Auto False Echo Suppression Range (2.5.10.2.)
and enter the value calculated in
step 2.
4. Go to
Auto False Echo Suppression (2.5.10.1.)
and press
RIGHT arrow
to open Edit Mode.
5. Select
Learn
. The device will automatically revert to
On
(Use Learned TVT) after a few
seconds.
Auto False Echo Suppression Range (2.5.10.2.)
Defines the endpoint of the Learned TVT distance. Units are defined in
Unit (2.3.1.)
.
Values
Range: 0.00 to 20.00 m
Default: 1.00 m
1. Press
RIGHT arrow
to open Edit mode.
2. Enter the new value and press
RIGHT arrow
to accept it.
3. Set
Auto False Echo Suppression (2.5.10.1.)
.
Hover Level (2.5.10.3.)
Defines how high the TVT (Time Varying Threshold) is placed above the noise floor of the echo
profile, as a percentage of the difference between the peak of the largest echo in the profile and
the noise floor. See
Auto False Echo Suppression (2.5.10.1.)
for an illustration.
Values
Range: 0 to 100%
Default: 40%
When the device is located in the center of the vessel, the TVT hover level may be lowered to
increase the confidence level of the largest echo.