Universal Calculation Support; Typical Flow Characterization - Siemens SITRANS LUT400 Operating Instructions Manual

Flume Size
(Diameter in feet)
• H-flumes come with a flat or sloping floor. The same flow table can be used
because error is less than 1%.

Universal calculation support

When the primary measuring device (PMD) doesn't fit one of the standard types, it can
be programmed using a universal characterization. When Universal is selected as the
2. 1 5. 1 . Primary Measuring Device (PMD)
PMD type [
2. 1 5.5. Universal Head vs. Flow
(
SITRANS LUT400 supports Universal curved (cubic spline) flow calculation shown in the
following chart. (The
Ratiometric or Absolute. Refer to your PMD manufacturer's documentation.)

Typical flow characterization

Characterization is achieved by entering the head and corresponding flow breakpoints,
either from empirical measurement or from the manufacturer's specification. Increasing
the number of defined breakpoints will increase the accuracy of the flow measurement.
Breakpoints should be concentrated in areas exhibiting the higher degrees of non linear
flow. A maximum of 32 breakpoints can be defined, with a minimum of four required. The
curve's end point is always specified by the parameters
2. 1 5.3.4. Maximum Flow at 20 mA
breakpoints available for definition.
Use as many breakpoints as required by the complexity of your PMD.
Volume
See on page 73 for more information and parameter
Flow
for characterization.
Page 116 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS
2.0
2.5
3.0
4.5
) must be entered to define the flow.
2.15.3.1. Method of Flow Calculation
Head Breakpoints
. These two parameter values are in addition to the 32
Point of Measurement
cm
18
23
28
41
], then both head and flow breakpoints
for universal support can be
Maximums (Max.
Head, Max. Flow)
Curved
2. 1 5.3.3. Maximum Head
2.15.5. Universal Head vs.
inches
7.25
9
10.75
16.25
and
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