Metrohm 739 Exchange unit - Manual (Page 40)

8. Troubleshooting
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6.3013.XXX and 6.3014.XXX Exchange Units, 8.110.1346
8. Troubleshooting
Problem Remedial action
Air bubbles are aspirated. – Is there sufficient reagent in the
bottle? (The aspirating tube has to
be immersed.) If necessary deaer-
ate reagent.
– Tighten all tubing connections.
– Clean stopcock, see section 4, if
necessary replace it.
Cylinder can not be filled without air
bubbles.
– Small air bubbles do not disturb,
see section 1.
– Keep glass cylinder and leading
edge of piston free of grease.
– Deaerate reagent if necessary.
Buret tip is blocked. – Soak in appropriate solvent. Store
buret tip in solvent, see section 1.
Dosed volume is not correct. – Carry out test according to Appli-
cation Bulletin No. 238.
– Check that there is no liquid at the
tubing connections or at the stop-
cock.
– Change glass cylinder and if nec-
essary piston.
"Piston" is leaking. There is liquid
below the piston.
– Change glass cylinder and if nec-
essary piston.
Stopcock is blocked/leaking. – Clean stopcock. Take care not to
have any solids in the threaded
holes, see section 4.
Stopcock can not be turned. – Clean stopcock, see section 4.
– Use PCTFE/PTFE stopcock.