Watson-Marlow 720UN and 720SN User Manual
53
UN
17.2 Footswitch operation and other re-
mote inputs and outputs with MemoDose
A footswitch can be used to trigger MemoDose dispensing as a hands-free alternative
to pressing
START
.
To operate MemoDose with a footswitch, briefly press the footswitch while the Mem-
oDose percentage screen is displayed.
The remote run/stop input is operational. If a dose is interrupted by a remote stop
signal, the dose will continue from where it stopped when the state is changed to
run.
Remote direction control is disabled. The leak-detection input is operational. All sta-
tus outputs are operational.
Note
: The keypad lock feature is particularly useful to prevent inadvertent dose
changes while using the MemoDose facility. Keypad lock continues to operate in Mem-
oDose if previously enabled; it can also be enabled while in MemoDose mode. See
14.5
Keypad lock
.
17.3 Flow calibration
The pump can display flowrate in millilitres per minute as well as speed in revolutions
per minute.
UN, SN
In the manual mode main screen, set the appropriate pump speed and direction
using the
UP
or
DOWN
keys and the
DIRECTION
key. A slower speed may
make it easier for the user to measure accurately - though it may not represent
the duty condition.
Place a suitable measuring vessel under the pump delivery tube.
Press
START
. The pump runs and fluid is pumped into the vessel. The volume
pumped is not important; but the greater the volume, the more accurate the
flow-per-revolution calculation will be. We suggest that the pumphead be run for
at least 10 revolutions, and at least 20 when small-bore pumping tube is used.
When a volume of fluid has been dispensed, it is necessary to stop the pump
and display the Calibration dose screen. This can be achieved in several ways.
1 Press the
STOP
key twice within half a second. The pump stops and immedi-
ately displays the MemoDose/Calibration screen. Use the
UP
or
DOWN
keys
to select
Calibration dose
. Press
ENTER
to confirm.
