Siemens Sitrans Probe LU Instruction Manual page 99

Oxley Creek WWTP Water Reclamation
(Probe LU Manual) Vendor Manual
2.7.7. TVT setup
First SITRANS Probe LU learns the echo profile. Then the learned profile, or part
of the learned profile, is used to screen out false echoes.
2.7.7.1. TVT Hover Level
2.7.7.2. TVT Type
2.7.7.7. Auto False Echo Suppression
1.
For an illustration, see
Auto False Echo Suppression
7ML19985JB02
Defines in percent how high the TVT (Time Varying Threshold) curve is
placed above the echo profile, with respect to largest echo. When
SITRANS Probe LU is located in the center of the vessel, lower this
parameter to prevent multiple echo detections.
Values
Selects the TVT curve to be used.
Hand
programmer
values
Enables a 'learned' TVT curve to be used in place of the default TVT curve.
Use this feature to ignore false echoes on the echo profile. Set Range
(Auto False Echo Suppression Distance) first.
Hand programmer
values
a. Rotate the instrument for best signal (lower false-echo amplitude).
b. Go to Range, and set the value (see page 94).
c. Open the menu
the option to change it.
d. Select The device will automatically revert to On (Use
Learned TVT) after a few seconds.
Display before Auto False Echo Suppression
, on page 94.
SITRANS Probe LU (PROFIBUS PA) – INSTRUCTION MANUAL
1
(default 33%)
Range: to
*
TVT short curve
TVT short flat
TVT long flat
TVT long smooth flat
TVT long smooth
TVT slopes
Off
On
the TVT curve
Doc Id: VM11
Active Date: 15/12/2006
and select
Display after
and
Page 93