Metrohm 840 PC Control 5.0 / Touch Control - Manual (Page 301)

5 Troubleshooting – Maintenance
PC Control / Touch Control
289
5.1.4 SET titrations
Problem Possible cause Remedy
Max. rate too low. Increase the min. rate under
Control parameters/User-def.
parameters.
Dosing at the end
takes too long and
the increments are
too small.
Unfavorable Stop
criterion.
Try increasing the Stop drift or
select a shorter Delay time.
The titration is not controlled
properly, i.e. individual
increments are not added at
the end.
- Select the Titration rate slow
under Control parameters.
- Select a larger Dynamics under
Control parameters/User-def.
parameters.
- Reduce the Max. rate under
Control parameters/User-def.
parameters.
- Reduce the Min. rate under
Control parameters/User-def.
parameters.
- Ensure that the solution is better
mixed and that the arrangement of
electrode and buret tip is optimal
(see Installation Instructions for
the Titrando).
"Overshoot"
Electrode responds too
slowly.
Replace the electrode.
Titration time too
long.
Unfavorable control
parameters.
- Select the Titration rate
optimal or fast.
- Select a smaller Dynamics under
User-defined parameters.
- Increase the Max. rate under
User-defined parameters.
- Increase the Min. rate under
User-defined parameters.
Reduce the Min. rate under
Control parameters/User-def.
parameters.
Results widely
scattered.
Electrode responds too
slowly.
Replace the electrode.