Measurement Range; Measurement Response - Siemens Sitrans LR250 Operating Instructions Manual

Example after Auto False Echo Suppression
false echo

Measurement Range

Near Range (2.5.1.)
Near Range programs SITRANS LR250 to ignore the zone in front of the antenna. The
default blanking distance is 50 mm (1.97") from end of antenna.
Near Range allows you to increase the blanking value from its factory default. But Auto
False Echo Suppression (2.5.10.1.) is generally recommended in preference to extending
the blanking distance from factory values.
Far Range (2.5.2.)
Far Range can be used in applications where the base of the vessel is conical or
parabolic. A reliable echo may be available below the vessel empty distance, due to an
indirect reflection path.
Increasing Far Range to 30% or 40% can provide stable empty vessel readings.

Measurement Response

Note: Units are defined in Unit (2.3.1.) and are in meters by default.
Response Rate (2.3.8.1.) limits the maximum rate at which the display and output respond
to changes in the measurement. There are three preset options: slow, medium, and fast.
Once the real process fill/empty rate (m/s by default) is established, a response rate can
be selected that is slightly higher than the application rate. Response Rate automatically
adjusts the filters that affect the output response rate
Response Rate
(2.3.8.1.)
* Slow
Medium
Fast
7ML19985JF04 SITRANS LR250 (PROFIBUS PA) – OPERATING INSTRUCTIONS
Auto False Echo
learned
Suppression Range
TVT
default
TVT
Fill Rate (2.3.8.2.)/Empty rate
(2.3.8.3.)
0.1 m/min (0.32 ft/min)
1.0 m/min (3.28 ft/min)
10.0 m/min (32.8 ft/min)
Auto False Echo
Suppression
Range set to 2 m
material
echo
echo
marker
Filter Time Constant
(2.6.8.1.)
10 s
10 s
0 s
Page 127