FIEDLER H1, Руководство пользователя

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Hydro Logger H1 User manual
56
electronics for ecology
FIEDLER
EXAMPLE 2: INSTANTANEOUS FLOW MEASUREMENT
The setup window for flow measurement is similar to the one described in the
previous chapter and therefore only new parameters or those that have a diffe-
rent meaning will be described here.
This option must be selected, for example, for a signal from an inductive
flowmeter. The parameter "Max. value" must correspond to the max. range of
the flowmeter.
When measuring the flow in open channels with a built-in gauge profile, the relati-
onship between the level in the gauge profile and the instantaneous flow is used.
Pressure probes and most ultrasonic probes have an output signal proportional
to the level and therefore the "Calculate flow from level" option must be selec-
ted for measurement, not only for pressure submersible level transducers, but
also when installing a US1200 ultrasonic transducer or when installing a
MICROFLEX ultrasonic probe.
In contrast to the level measurement described in the previous window, the
Delta parameter can no longer be replaced by the additive coefficient A0, be-
cause it is entered in the set flow rate units, whereas Delta is always intended
for zero level displacement.
The list of measuring
points shows the 14 most
frequently occurring profi-
les for measuring instanta-
neous flow in an open
channel with predefined
coefficients of the con-
sumption equation.
This menu is supplemen-
ted by the possibility of
custom setting of the co-
efficients of the consump-
tion equation A0 to A2 (op-
tional profile) and the ta-
bular input of the depen-
dence between level and flow.
The consumptive equation is most often of the form :
Flow = A
1
* Level
A
2
[ m
3
/s, m]
If necessary, it can be supplemented with the additive coefficient A
0
. In the case
of more complex composite gutters, additional auxiliary coefficients A3 to A6
and the heights of the built-in gutters H1 and H2 are added to the above coeffi-
cients (see figure on this page).
There can be two tables (for two different measuring channels) and they are
used to record the tabular relationship between the level height [mm] and the
value of instantaneous flow [l/s]. Table 1 has 30 rows and Table 2 has 20 rows.
Only integers in the range from 0 to 65535 can be written to the tables. If the
flow rate with a resolution of e.g. 2 decimal places is to be stored in the table,
then the flow rate 100 times greater without decimal point is entered into the
S i g n a l
p r o p o r t i o n a l t o
f l o w r a t e
C a l c u l a t i o n o f t h e
f l o w r a t e f r o m t h e
s u r f a c e
M e a s u r i n g p o i n t
Ta b l e