User's Manual

7ML19985JM01 SITRANS LR 460 – INSTRUCTION MANUAL Page 68
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Parameters
2.5.5. TVT (Auto False Echo Suppression) setup
First SITRANS LR 460 learns the echo profile. Then the learned profile, or part of
the learned profile, is used to screen out false echoes.
2.5.5.1. TVT Hover Level
1
Defines in percent how high the TVT (Time Varying Threshold) curve is
placed above the echo profile, with respect to largest echo. When
SITRANS LR 460 is located in the center of the vessel, lower this
parameter to prevent multiple echo detections.
2.5.5.6. Auto False Echo Suppression
1
Enables a ’learned’ TVT curve to be used in place of the default TVT curve.
Use this feature to ignore false echoes before the material echo. Set
Range (Auto False Echo Suppression Distance) first.
a. Rotate the instrument for best signal (lower false-echo amplitude).
b. Go to Range, and set the value (see details below).
c. Open the menu Device – Auto False Echo Suppression and select
the option to change it.
d. Select Learn. The device will automatically revert to On (Use
Learned TVT) after a few seconds.
2.5.5.7. Range (Auto False Echo Suppression Distance)
Defines the endpoint of the Learned TVT distance.
a. Go to Input > Detailed Setup > TVT Setup > Range.
b. Determine the actual distance from the antenna reference point to
the material surface.
c. Subtract 0.5 m (20") from this distance, and enter the result.
Note: The Auto False Echo Suppression parameters are for authorized Siemens
Milltronics Service personnel or technicians familiar with Siemens Milltronics
echo processing techniques. View the echo profile first, before attempting to
modify these parameters.
1.
For an illustration, see Display before Auto False Echo Suppression and Example after
Auto False Echo Suppression , page 69.
Values
Range: 0 to 100%
Default: 40%
Values
0 Off
1 Enable Auto False Echo Suppression
2 "Learn" the TVT curve