Metrohm 746 VA Trace Analyzer - Manual (Page 58)

3.7 Auxiliary electrode
746 VA Trace Analyzer / 747 VA Stand
3-31
3.7 Auxiliary electrode
3.7.1 Construction
The following electrodes can be used as the auxiliary electrode 60 60 (AE):
• 6.0343.000 Pt auxiliary electrode
supplied as standard
• 6.1241.020 Electrode holder and
6.1247.000 Glassy carbon tip
together form the glassy carbon auxiliary electrode
available as an option
The construction of the two auxiliary electrodes and the designations of the individ-
ual parts are shown in Fig. 18.
3.7.2 Startup procedure
The 6.0343.000 Pt auxiliary electrode supplied as standard can be inserted directly
in the 747 VA Stand ( → 2), whereas the GC auxiliary electrode available as an op-
tion must first be assembled ( → 1):
1 Assembly of the GC auxiliary electrode
• Insert glassy carbon tip 138 138 through the locking ring 137 137 into the elec-
trode holder 136 136 as far as it will go.
Glassy carbon is a brittle, easily breakable material and must therefore
be inserted carefully into the electrode holder and handled gently.
If the GC tip breaks, the part remaining in the holder can be removed
by pulling out the locking ring 137 137.
2 Install auxiliary electrode in 747 VA Stand and connect
• Insert auxiliary electrode 60 60 in opening 72 72 of the measuring head 41 41
(see Fig. 9).
• Attach electrode cable 58 58 (AE) to auxiliary electrode 60 60:
Push cable lug under the screw and tighten screw firmly.
• Turn auxiliary electrode 60 60 so that the electrode cable 58 58 points to the
rear and not to the side (in the latter position it may become kinked and
damaged when cover 24 24 is closed).