Metrohm 894 Professional CVS User Manual
Page 92
7.1 894 Professional CVS
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894 Professional CVS
Problem
Cause
Remedy
The measuring vessel con-
tains too little solution or is
empty.
Check the fill level in the measuring vessel and
add solution if necessary.
The electrode tip of
the working elec-
trode and/or the
auxiliary electrode
shows copper
deposits.
An incorrect potential has
been applied because the
reference electrode is
defective.
￭
Check the reference electrode; perform
maintenance procedure in accordance with
the electrode leaflet, if necessary.
￭
Dip the electrode tip of the working elec-
trode and/or the auxiliary electrode into
concentrated nitric acid for 1 to 2 seconds
and then thoroughly rinse with distilled
water.
An incorrect potential was
applied because the refer-
ence electrode is not con-
nected.
￭
Check the electrode connectors.
￭
Dip the electrode tip of the working elec-
trode and/or the auxiliary electrode into
concentrated nitric acid for 1 to 2 seconds
and then thoroughly rinse with distilled
water.
An incorrect potential was
applied because the mea-
suring vessel contains too
little measuring solution.
￭
All three electrodes must be immersed in
the measuring solution.
￭
Dip the electrode tip of the working elec-
trode and/or the auxiliary electrode into
concentrated nitric acid for 1 to 2 seconds
and then thoroughly rinse with distilled
water.
The measured val-
ues are widely scat-
tered.
The solutions are pipetted
manually.
Use an 800 Dosino with dosing unit.
The solutions are not
added via the pipetting
opening.
Add solutions only via the pipetting opening
(5-
The measurement
curves are noisy.
Contact problem at the
driving axle (6.1204.510 or
6.1204.520).
￭
Remove the abrasion residue from the driv-
ing axle.
￭
Replace the driving axle.
The measuring sig-
nal for Cu VMS fluc-
tuates.
The ambient and/or solu-
tion temperature is not
constant.
Keep the ambient and solution temperature
stable during measurements (±4 °C).
The reference potential
drifts off.
Perform maintenance procedure for the refer-
ence electrode in accordance with the elec-
trode leaflet. However, for CVS analyses,