VEGA VEGASON 71 - D - Manual (Page 25)

VEGASON 71 - D 25
7.4 Impulse value for sampling relay
(continuation)
Example
One impulse on the sampler per 50000 m 3
corresponds to 5000 • 10 m 3
- Mode 0 - 87 , flow volume / impulse = 5000
- Mode 0 - 88 , multiplier = 1
- Mode 0 - 89 , time dependent control
every 24 hours = 24
Programming
Flow volume / impulse = 5000
•
Enquire mode 0 - 87 in the MODEFIELD
• Program figure
5000
in the PARAMETER FIELD
• Then store with STO
Multiplier = 1
•
Enquire mode
0 - 88
in the MODEFIELD
• Program figure 1 in the PARAMETER FIELD
• Then store with STO
Time dependent control = 24
•
Enquire mode 0 - 89 in the MODEFIELD
• Program figure 24 in the PARAMETER FIELD
• Then store with STO
7.5 Definition of the min. flow volume
limit
With open flumes sediment build-up can cause a zero
error. VEGASON 71 - D would therefore permanently
detect a low flow which will be considered for flow volume
counting.
A minimum flow volume limit can be set in mode 0 - 90 to
eliminate this problem. If the flow is below this limit, this
value is not considered for the determination of the flow
volume.
This parameter adjustment does not influence the level
proportional or flow proportional output via current outputs
or switching relays.
Programming example
Min. flow volume limit at 0,5 %
•
Enquire mode 0 - 90 in the MODEFIELD
• Program figure 000.5 in the PARAMETER FIELD
• Then store with STO
7.6 Calculation examples of the max.
flow
The expression "Max. flow" considers the following flume
specific factors
- geometry
- flow rate
- flume material
The respectively valid value can therefore only be stated
exactly by the flume manufacturer.
If this information to an available flume or weir is not
available, it can be approximated.
Therefore the following schedules and fundamentals can
be used.
It must be observed that for the various types of flumes
and weir forms, different versions are possible, which are
however not considered in the formulars.
Supplementary it is recommended to determine and
observe the frame conditions defined in the literature for
flow measurement (surface of flume, flow rate etc.).
The own manufacture of flumes and weirs based on the
following versions is not possible.
For the following flumes, flow schedules and calculation
examples are stated
Page
- Venturi flume 26
- Trapezoidal weir (Cipoletti) 27
- Rectangular weir without throat 28
- Rectangular weir with throat 29
- V-Notch 30
- Palmer-Bowlus-flume 31
Conversion information
- Liter/sec • 3,6 = m 3 /h
1
- m 3 /h • ––– = Liter/sec
3,6
- Example 10 Liter/sec ^ 36 m 3 /h
7 Output results