Metrohm 757 VA Computrace - Manual (Page 42)

3 Installation
757 VA Computrace – Hardware
38
3.6 Auxiliary electrode
3.6.1 Construction
The following electrodes can be used as the auxiliary electrode 39 (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. 14.
3.6.2 Startup procedure
The 6.0343.000 Pt auxiliary electrode supplied as standard can be inserted directly
in the 757 VA Computrace Stand (→ 2), whereas the GC auxiliary electrode avail-
able as an option must first be assembled (→ 1):
1 Assembly of the GC auxiliary electrode
• Insert glassy carbon tip 117 through the locking ring 116 into the elec-
trode holder 115 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 116.
2 Install auxiliary electrode in 757 VA Computrace Stand and
connect
• Insert auxiliary electrode 39 in opening 51 of the measuring head 20
(see Fig. 6).
• Attach electrode cable 37 (AE) to auxiliary electrode 39:
Push cable plug under the screw and tighten screw firmly.
• Turn auxiliary electrode 39 so that the electrode cable 37 points to the
rear and not to the side (in the latter position it may become kinked and
damaged when cover 1 is closed).