Siemens SITRANS LR120 Modbus Operating Instructions Manual page 23

Installing/mounting
4.4 Measurement setup - Flow
Flow formula:
If the flow formula of your flume is known, you should select this option, as the
accuracy of the flow measurement is highest here.
•
Manufacturer definition:
If you use a Parshall flume from the manufacturer ISCO, this option must be selected.
This gives you a high accuracy of flow measurement with easy configuration.
Alternatively, you can also take over Q/h table values provided by the manufacturer
here.
•
•
Note
Detailed project planning data can be found at the channel manufacturers and in the
technical literature.
The following examples serve as an overview for flow measurement.
Rectangular overfall
1
2
3
4
Figure 4.9
16
Flow formula: Q = k x h
ISCO-Parshall-Flume
Q/h table (assignment of height with corresponding flow in a table)
Overfall orifice (side view)
Upstream water
Tailwater
Overfall orifice (view from tailwater)
Flow measurement with rectangular flume: h
flume
exp
= max. filling of the rectangular
max.
Operating Instructions, 10/2022, 62709-76-01, A5E49829030
SITRANS LR120 Modbus