Siemens SITRANS LUT400, Operating Instructions Manual

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A5E33329501 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS Page 59
mm
mmm
Commissioni
ng
Flow application example
Parshall Flume
In this example, a 12 inch (0.305 m) Parshall Flume has been installed in an open channel.
As per the supplier’s data sheet, the device has been rated for a maximum flow of 1143 m
3
per hour at a maximum head of 0.6 m.
The Parshall Flume is considered an exponential device, therefore the supplier’s data
sheet includes a flow exponent value of 1.522.
The SITRANS LUT400, and the XRS-5 transducer have been installed 1.6 m above the
channel beside the TS-3 external temperature sensor.
During intermittent peak flow times, the head level can be expected to rise at a rate of
approximately 0.12 m/minute. The application also calls for a flow sampler to be activated
every 1000 m
3
, or 24 hours (whichever comes first), and for a fail-safe alarm to activate in
the event of a loss of echo or cable fault.
Q
C
2
/
3
C
Zero
Head
Front View
Plan View
transducer
Side View
Low Cal.
= 1.6 m
XRS-5
Head
= 0.6 m
TS-3
High Cal.
= 1.0 m
C = Converging dimension