User's Manual

Page 96 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE03
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Parameters
2.8.7.2. Auto False Echo Suppression Range
Specifies the range within which Learned TVT is used (see Auto False Echo
Suppression (2.8.7.1.) on page 130 for more detail).
a) Calculate range according to Auto False Echo Suppression (2.8.7.1.)
steps a) and b).
b) Press RIGHT arrow to open Edit mode.
c) Enter the new value and press RIGHT arrow to accept it.
d) Set Auto False Echo Suppression (2.8.7.1.).
2.8.7.3. Hover Level
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 Before
Auto False Echo Suppression on page 94 for an illustration.
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.
2.8.7.4. Shaper Mode
Enables/disables the TVT shaper.
2.8.8. TVT shaper
Adjusts the TVT (Time Varying Threshold) at a specified range (breakpoint on
the TVT). This allows you to reshape the TVT to avoid unwanted echoes. There
are 40 breakpoints arranged in 5 groups. (We recommend using SIMATIC PDM
to access this feature.)
Values
Range: 0.00 to 20.00 m
Default: 1.0 0 m
Related parameters Units (1.4.)
Values
Range: 0 to 100%
Default: 40%
Options
ON
*OFF
Notes:
• The range is –100 to 100 bits. With 2 bits per dB this gives a range of –50 to
50 dB.
• Shaper Mode (2.8.7.4.) must be turned ON in order for TVT shaper points to
be transferred