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6.3
Pump dispenser
The test liquid is applied from the built-in micro-pump via the pump
applicator unit. It is suggested the pump system is used for a single standard
test liquid (e.g. water or fountain solution).
Use different tuning for each test liquid to avoid contamination!
To pump liquids of higher viscosity or to determine the wetting hysteresis
(advanced/receding contact angles), it will be necessary to use the optional
PG Dosing Unit.
The integrated micro pump is designed for a standard liquid (e.g. water)
where the droplet size can be set in steps of 0,5 µL.
•
Press the PUMP button to pump out a new droplet.
•
If PUMP is pressed until the LED is lit, the droplet is slowly lowered
towards the test surface, which is recommended for measurements
in Static Mode;
•
If PUMP is pressed momentarily, the LED will blink while the droplet
is pumped out. It is then lifted a short distance from which it is
dropped towards the surface. This approach is recommended for
Dynamic Mode measurements.
•
Press PUMP a second time during the pump sequence to inhibit
application of the droplet.
The liquid system is filled in the following way:
a)
Place the instrument on top of a flat surface
b)
Locate the tiny air hole on top of the white container lid. Use the
attached one millilitre syringe with the RED tip to fill the container
with distilled water.
NOTE:
DO NOT use tap water, as this will leave residuals inside the liquid
system!
c)
Insert the RED dispensing tip into the air hole to fill the container.
Check top of liquid container to see when liquid container is full
(See picture)
d)
Check the pump lid screw is tightened. (see picture)
e)
Fill the pump tubing like this:
- Set the volume selector to position FILL.
- Press PUMP and the pump will be activated to give 50 pump
strokes before it stops.
This volume (25 µL) may produce a small droplet at the dispensing
tip. If not, press once more on the PUMP button to restart pump.
When all air is removed and a droplet appears at the dispensing tip:
press and hold the PUMP button until pump stops.
f )
Set the volume selector to “4,0 µL”, which is the default droplet size
for testing (see chapter “ Miscellaneous” ).
g)
The instrument is now ready for a test (see Section 8.).
Tighten the pump lid screw
Filling the Liquid Container
