Metrohm 797 VA Computrace - Manual (Page 42)

2 Installation
797 VA Computrace / Hardware-Manual 8.797.8001EN
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2.4 Rotating disk electrode (RDE)
The rotating disk electrode (RDE) can be used in place of the MME in the 797 VA
Computrace Stand with different electrode tips as a working electrode. Version
2.797.0030 is delivered solely with a rotating plating electrode. For operation of the
rotating disk electrode (RDE) the following accessories are required (see also section
4.3):
• 6.1204.210 Driving axle for rotating disk electrode (RDE)
with titanium axle
• 6.1204.220 Driving axle for rotating disk electrode (RDE)
with titanium axle and mercury contact
• 6.1204.XXX Electrode tip for rotating electrode
6.1204.110 GC (Glassy Carbon)
6.1204.120 Pt unpolished, 2 mm disk diameter
6.1204.130 Ag
6.1204.140 Au for Hg determination
6.1204.150 Au for As determination
6.1204.160 Pt polished, 2 mm disk diameter for CVS
6.1204.170 Pt polished, 3 mm disk diameter for CVS
6.1204.180 Ultra Trace Graphite
6.1204.190 Pt polished, 1 mm disk diameter for CVS
• 6.2709.040 Stopper for closing the MME opening
• 6.2802.000 Polishing kit for 6.1204.XXX Electrode tips
(Pt, Ag, Au, GC)
• 6.2827.000 Trimming tool for 6.1204.180 Electrode tip
(Ultra Trace Graphite)
It is recommended to use RDE tips (except Pt) only together with a
glassy carbon auxiliary electrode!
2.4.1 Construction and startup of the RDE
The rotating disk electrode RDE comprises the two parts drive shaft 99 (6.1204.210)
and electrode tip 98 (6.1204.2x0), which must be screwed together.
The procedure for installing the RDE in the measuring head arm of the 797 VA Com-
putrace Stand is described in detail in section 2.2.4. The fully equipped measuring
head arm with the RDE is illustrated in Fig. 12.
2.4.2 Regeneration of RDE
The RDE is a solid electrode with a stationary surface. This becomes contaminated
with the products of the electrode redox processes with increasing use
For regeneration please observe the information on the leaflet enclosed with the RDE.