English (GB)
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6.9 Flow measurement
Applies to DDA-FCM control variant.
The pump accurately measures the actual flow and
displays it. Via the 0/4-20 mA analog output, the
actual flow signal can easily be integrated into an
external process control without additional
measuring equipment (see section
).
The flow measurement is based on the indicator
diagram as described in section
The accumulated length of the discharge phase
multiplied by the stroke frequency produces the
displayed actual flow. Faults e.g. air bubbles or
backpressure that is too low result in a smaller or
larger actual flow. When the "
AutoFlowAdapt
"
function is activated (see section
), the pump compensates for
these influences by correction of the stroke
frequency.
6.10
AutoFlowAdapt
Applies to DDA-FCM control variant.
The "
AutoFlowAdapt
" function is activated in the
"
Setup
" menu. It detects changes in various
parameters and responds accordingly in order to
keep the set target flow constant.
This function processes information from the
pressure sensor in the dosing head. Errors detected
by the sensor are processed by the software.
The pump responds immediately regardless of the
operation mode by adjusting the stroke frequency or
where necessary compensating for the deviations
with a corresponding indicator diagram.
If the target flow cannot be achieved by the
adjustments, a warning is issued.
"
AutoFlowAdapt
" operates on the basis of the
following functions:
•
FlowControl
: malfunctions are identified (see
section
).
•
Pressure monitoring
: pressure fluctuations are
identified (see section
).
•
Flow measurement: deviations from the target
flow are identified (see section
).
Example of "
AutoFlowAdapt
"
Pressure fluctuations
The dosing volume decreases as backpressure
increases and conversely the dosing volume
increases as the backpressure decreases.
The "
AutoFlowAdapt
" function identifies pressure
fluctuations and responds by adjusting the stroke
frequency. The actual flow is thus maintained at a
constant level.
6.11
Auto deaeration
Dosing degassing media can result in air
pockets in the dosing head during breaks in
dosing. This can result in no medium being dosed
when restarting the pump. The "
Setup
>
Auto
deaeration
" function performs pump deaeration
automatically at regular intervals.
Software-controlled diaphragm movements
encourage any bubbles to rise and gather at the
discharge valve so that they can be removed on the
next dosing stroke.
The function works:
•
when the pump is not in the "Stop" operating
state
•
during breaks in dosing (e.g.
External stop
, no
incoming pulses, etc.).
6.12
Key lock
The key lock is set in the "
Setup
>
Key lock
"
menu by entering a four-digit code. It protects the
pump by preventing changes to settings. Two levels
of key lock can be selected:
It is still possible to navigate in the "
Alarm
" and "
Info
"
main menu and reset alarms.
6.12.1 Temporary deactivation
If the "
Key lock
" function is activated but settings
need to be modified, the keys can be unlocked
temporarily by entering the deactivation code. If the
code is not entered within 10 seconds, the display
automatically switches to the "
Operation
" main
menu. The key lock remains active.
6.12.2 Deactivation
The key lock can be deactivated in the "
Setup
>
Key
lock
" menu via the "
Off
" menu point. The key lock is
deactivated after the general code "2583" or a
pre-defined custom code has been entered.
Note
Strokes which cannot be analysed
(partial strokes, pressure differential
which is too low) are provisionally
calculated based on the setpoint value
and displayed.
Note
Dosing accuracy is increased when
"
AutoFlowAdapt
" is activated.
Note
The diaphragm movements can
displace small volumes into the
discharge line. When dosing strongly
degassing media, this is however
virtually impossible.
Level
Description
Settings
All settings can only be changed by
entering the lock code.
The [Start/stop] key and the [100%]
key are not locked.
Se
keys
The [Start/stop] key and the [100%]
key and all settings are locked.
