Metrohm 884 Professional VA, Руководство - Краткие инструкции

Страница: 78 / 91

6.1 List of faults
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
70
￭￭￭￭￭￭￭￭
884 Professional VA
Problem Cause Remedy
One of the electrodes (nor-
mally the working or refer-
ence electrode) is not
operational. Service the electrode or replace the electrode
in the case of a solid-state electrode (e.g. plati-
num RDE).
The stirrer or RDE is not
rotating properly. Inspect the drive. Service or replace the drive if
necessary.
For other application-specific problems,
observe
(see Chapter 6.1.2, page 70) and
(see Chapter 6.1.3, page 78) .
The measuring ves-
sel overflows. Incorrect pump times have
been defined in
viva .
Adjust the pump times.
The volumes defined in the
dosing commands in
viva
are too large.
Reduce the volumes.
The peak is no lon-
ger recognized. The reference potential has
shifted. Perform the maintenance procedure for the
reference electrode in accordance with the
electrode leaflet. You can find more detailed
information at
http://va-electrodes.met-
rohm.com .
One or more of the solu-
tions in use (water, electro-
lyte, VMS, etc.) has
become contaminated. Apply fresh solution; use water from a differ-
ent source.
6.1.2 884 Professional VA for VA trace analysis
Problem Cause Remedy
A peak is not found
in either the sample
or for the standard
addition. The peak is not within the
sweep range. Check Start potential and End potential of
the sweep in viva .
The electrolyte solution is
too old. Produce new electrolyte solution. Organic
additives may only last 1 day or less.
Organic constituents inter-
fere with analysis. Carry out UV digestion or equivalent sample
preparation.
The complexing agent has
been omitted (adsorptive
stripping voltammetry). Use complexing agent.
No drops form at the capil-
lary.
￭
Check the MME pro.
￭
Adjust the needle and capillary.