Troubleshooting - Roth Rotilabo II Mode D'emploi

17. Troubleshooting

Problem
Piston moves with difficulty or
is stuck
Filling not possible
Dispensing not possible
Discharge tube cannot be
mounted sufficiently
Air bubbles in the instrument
Dispensed volume is too low
Leaking liquid between instru-
ment and bottle
48
Possible cause
Formation of crystals, dirty
Volume adjusted to minimum
setting
Filling valve stuck
Discharge valve stuck
Discharge valve is not screwed
in deeply enough
Reagent with high vapor pressure
has been drawn in too quickly
Valve screw connections loose
The instrument has not been
primed
Filling tube is loose or damaged Push the filling tube on firmly. If necessary
Valves not firmly connected or
damaged
Filling tube is loose or damaged Cleaning procedure (see page 40-41).
Filling valve is loose or damaged Cleaning procedure (see page 43-44).
Volatile reagent dispensed
without sealing ring
moisture-sensitive or CO
sensitive media
Corrective action
Stop dispensing immediately. Loosen
piston with circular motion, but do
not disassemble. Follow all cleaning
instructions (page 40-41).
Set to required volume (see page 35).
Unscrew the filling valve from the valve
block, clean it, replace the filling valve if
necessary. If the valve is stuck use a
200 µl pipette tip to loosen it (see page
43). If necessary replace the filling valve
with sealing washer.
Unscrew the discharge valve from the
valve block, clean it, replace the discharge
valve if necessary (see page 42), use a
200 µl plastic tip to loosen any ball valve
that is stuck.
Tighten the discharge valve with the
mounting tool until it meets the stop so
that the threads are no longer visible.
Slowly draw in reagent.
Tighten the valves firmly with the mount-
ing tool.
Prime the instrument (see page 34).
cut off approx. 1 cm of tube at the upper
end and re-connect it or replace filling
tube.
Cleaning procedure (see page 40-41).
Tighten the valves using the mounting
tool.
Push the filling tube on firmly. If neces-
sary, cut off approx. 1 cm of the tube
at the upper end and re-connect it or
replace filling tube (see page 43).
Tighten the valves using the mounting
tool. If necessary, replace filling valves.
Mount sealing ring (see page 36).
Mount the seal ring for the valve block
2
(see page 36) and use a drying tube filled
with suitable absorbent (see page 36).