VWR 2 Manual De Instrucciones página 10

Troubleshooting
Review the information in the table below to troubleshoot
operating problems.
Problem Cause
The tip is emptied
too fast.
Droplets of liquid
remain
The tip wettability
in the pipettor tip.
has increased due
to extensive use.
The pipettor tip
immersion is too
shallow
Droplets of air The pipettor tip is
appear in the liquid incorrectly pressed
aspirated onto the pipette
into the tip. shaft.
The tip is damaged
or worn out due to
extensive use.
The pipettor tip is
incorrectly pressed
onto the pipette
shaft.
The shaft nut is loose
(Fig. 2F) in the mod-
els VWR2-VWR1000
The pipettor
incorrectly
aspirates the liquid
or liquid drops out
from the tip.
The sealing surface
of the shaft is
cracked or scored.
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Solution
Decrease the speed of pressing
the pipettor pushbutton.
Replace the tip
with a new one.
Immerse the tip deeper
according to the instructions
(page 13).
Press the pipettor firmly.
Replace the tip with a new one.
Press the pipettor tip firmly.
Tighten the shaft nut.
Remove the tip ejector.
Unscrew the shaft nut, inspect
the shaft and the piston
assembly. Replace the dam-
aged parts. When reassembling
the pipettor, the nut should be
hand tightened. In the models
VWR2 - VWR20, the damage
of the shaft may also cause a
damage of the piston assembly.
Replace the damaged parts.
When reassembling the
pipettor, the nut should be
hand tightened. To remove the
tip ejector in models VWR5000
andVWR10000, remove
the ejector pushbutton (Fig. 2N)
and using a screw driver
unscrew the tip ejector
by turning the screw driver
counter-clockwise.
Problem Cause
Damage to the piston
or seal due to
prolonged use
with the aggressive
liquids.
The pipettor
is reassembled
improperly.
The pipettor
incorrectly
aspirates the liquid
or liquid drops out
from the tip.
No lubricant on the
sealing elements.
Contamination of the
inside of the pipettor
caused by
extensive aspiration
of chemically aggres-
sive liquids or
because liquid got
inside the pipettor.
If the problem continues after carrying out the above
steps, contact your VWR representative.
Before returning the pipettor, please ensure that the
pipettor is completely free of any chemical, radioactive or
microbiological contamination which could pose a threat
during transport and repair. As far as it is possible, clean
the pipettor.
Version: 1
Issued 17/03/2014
ENGLISH
Solution
Replace the piston, seal
and O-ring. Rinse the inside
of the shaft in distilled water
and dry.
Lubricate the seal and O-ring
with the lubricant, that has been
included with each pipettor.
The replacement of the piston
requires conducting
of the calibration procedure.
Note: The parts of VWR2
and VWR10 pipettor should
be lubricated evenly with
a minimum amount of lubricant.
Disassemble the pipettor and
reassemble it, observing
the proper sequence of steps
(Fig. 2).
Remove the tip ejector.
Unscrew the shaft nut, remove
the shaft, piston assembly, seal
and O-ring.
Rinse the removed parts
in distilled water and dry
thoroughly.
Lightly lubricate the inside
surfaces of the seal and the
O-ring with the included
lubricant. Reassemble
the pipettor in the reverse order.
Remove the tip ejector.
Unscrew the nut, remove
the shaft, piston assembly, seal
and O-ring. Rinse
the removed parts with distilled
water and dry thoroughly.
Lightly lubricate the inside
surfaces of the seal and the
O-ring with the lubricant.
Reassemble the pipettor
in the reverse order.
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