CNGmass DCI
Commissioning
Hauser
43
6.3.2
Quick Setup "Pulsating Flow"
!
Note!
The "Pulsating Flow" Quick Setup is only available if the device has a current output or a pulse/
frequency output.
Certain types of pump such as reciprocating, peristaltic and cam-type pumps, for example, create a
flow characterized by severe periodic fluctuations. Negative flows can occur with pumps of these
types on account of the closing volume of the valves or valve leaks.
!
Note!
Before carrying out the Quick Setup "Pulsating Flow", the Quick Setup "Commissioning" has to be
executed,
A0001213
Fig. 23:
Flow characteristics of various types of pump
A
With severely pulsating flow
B
With low pulsating flow
1
1-cylinder cam pump
2
2-cylinder cam pump
3
Magnetic pump
4
Peristaltic pump, flexible connecting hose
5
Multi-cylinder reciprocating pump
Severely pulsating flow
Once several device functions have been configured in the "Pulsating flow" Quick Setup menu, flow
fluctuations of this nature can be compensated over the entire flow range and pulsating fluid flows
measured correctly. You will find detailed instructions on how to use this Quick Setup in the
following section.
!
Note!
It is always advisable to work through the "Pulsating flow" Quick Setup menu if there is any
uncertainty about the exact flow characteristic.
Slightly pulsating flow
If flow fluctuations are no more than minor, as is the case, for example with gear-type, three-
cylinder or multi-cylinder pumps, it is
not
absolutely necessary to work through the Quick Setup
menu.
In cases of this nature, however, it is advisable to adapt the functions listed below in the function
matrix (
È
"Description of Device Parameters" manual) to suit local process conditions in order to
ensure a stable, unvarying output signal:
• Measuring system damping: "FLOW DAMPING" function
→
Increase value
• Current output damping: TIME CONSTANT function
→
increase the value
Q
Q
Q
Q
Q
t
t
t
t
t
1
3
2
5
4
A
B