Measurement Range - FlowLine EchoWave LG10 Series Manual

Getting Started
UNDERSTANDING MEASUREMENT RANGE
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EchoWave level transmitters have small dead band areas at both the top and bottom of the probe. It is due to
the presence of unavoidable signal disturbances at both ends of the probe. In these dead band areas the
measurements are non-linear or have reduced accuracy. Therefore, it is not recommended to actually measure
level within these dead band areas. Their length depends on the probe type and the reflectivity
(i.e. dielectric constant) of the liquid to be measured.
The Measurement Range of LG10/LG11 series extends between the
top and bottom dead band areas; this is the area in which a sensor will
have the specified measurement performance. It is recommended that
the maximum and minimum levels to be measured in the tank are
actually within the Measurement Range of the sensor. The span
between the lower range value [4mA] and the upper range value [20mA]
of the current output is proportionally equal from 0 to 100% of your
continuous level measurement reading. It is recommended that the span
between these two range values stays within the Measurement Range.
The [Top Dead Band], closest to the threads, is set to 4" (100mm). This
is measured from the bottom of the nut down to the probe. This is
consistent for all styles of probe. Note: the measurement location for the
Top Dead Band is different to the measurement location for the probe
length.
The [Bottom Dead Band], closest to the end of the probe, is set to 2"
(50mm). This is measured from the end of the probe on rod and coaxial
probes. For cable probes, it is measured from the top of the counter-
weight. The counter-weight must be included with the dead band as the
sensor's inactive area.
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Section Two
MN300840 REV A8