Troubleshooting - BRAND Dispensette S Mode D'emploi

12 Troubleshooting

12 Troubleshooting
Problem
Piston sluggish or stuck
Filling not possible
Dispensing not possible
Discharge tube (with or
without recirculation
valve) cannot be
mounted sufficiently
Air bubbles in the instru-
ment
Dispensed volume too
low
Leaking liquid between
instrument and bottle
62
Operating manual
Possible cause
Crystal deposits,
Contaminants
Volume adjusted to minimum
setting
Filling valve stuck
Discharge valve stuck
Discharge valve is not screwed in
deeply enough
Reagent with high vapor pres-
sure has been drawn in too
quickly
Valve screw connections loose
The instrument has not been
primed
Filling tube is loose or damaged
Valves not firmly connected or
damaged
Filling tube is loose or damaged
Filling valve is loose or damaged Carry out cleaning (Cleaning, p. 56).
Recirculation tube not con-
nected
Volatile reagent dispensed with-
out sealing ring
Corrective action
Stop dispensing immediately. Loosen
piston with circular motion, but do
not disassemble.
Carry out cleaning (Cleaning, p. 56).
Set the desired volume (Dispens-
ing, p. 49).
Unscrew the filling valve from the
valve block and clean it. If the valve
ball is stuck, use a 200 µl plastic tip to
dislodge it (Dislodging a stick valve
ball, p. 61). If necessary, replace the
filling valve.
Unscrew the discharge valve from the
valve block, clean it and replace if
necessary. If the valve ball is stuck,
use a 200 µl plastic tip to dislodge it.
Tighten the discharge valve with the
assembly tool until it meets the stop
so that the threads are no longer visi-
ble.
Slowly draw in reagent.
Tighten the valves firmly with the as-
sembly tool.
Prime the instrument (Priming, p. 47).
Push the filling tube on firmly. If nec-
essary cut off approx. 1 cm of tube at
the upper end and re-connect it or re-
place filling tube.
Carry out cleaning (Cleaning, p. 56).
Tighten the valves using the assembly
tool.
Carry out cleaning (Cleaning, p. 56).
Push the filling tube on firmly. If nec-
essary cut off approx. 1 cm of tube at
the upper end and re-connect it or re-
place filling tube (Replacing discharge
tube, p. 60).
Tighten the valves using the assembly
tool. If necessary, replace filling
valves.
Connect recirculation tube (First
Steps, p. 46, Fig. 3).
Install sealing ring for valve block
(First Steps, p. 46).
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