Siemens SITRANS LUT400 Series - Pmds with Exponential Flow to Head Function; Applicable Weir Profiles

Page 100 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS A5E33329501
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General Operation
PMDs with Exponential Flow to Head function
For Primary Measuring Devices (PMDs) that measure flow by an exponential equation,
use these parameters. Ensure that you use the correct exponent for your PMD; the values
below are samples only.
Standard Weirs
Applicable weir profiles
Parameter Value
2.15.1. Primary Measuring Device (PMD) Exponential Devices
2.15.3.2. Flow Exponent
Weir Type
Value
a
a.
Values are samples only. Consult weir manufacturer’s documentation for cor-
rect flow exponent.
V-notch
Suppressed rectangular
Cipolletti or trapezoidal
Sutro or proportional
2.50
1.50
1.50
1.00
2.15.3.3. Maximum Head
2.15.3.4. Maximum Flow at 20 mA
2.15.3.7. Flowrate Units
2.2.5. Far Range
2.15.4.1. K Factor
b
b.
Required for exponential device absolute calculation only.
3 to 4 x h
max
weir profile
transducer
h
V-notch or
triangular
suppressed
rectangular
cipolleti or
trapezoidal
sutro or
proportional