Metrohm 746 VA Trace Analyzer - Manual (Page 44)

3.4 Multi-mode electrode (MME)
746 VA Trace Analyzer / 747 VA Stand
3-17
2 Draw up mercury
• Attach needle 112 112 to syringe 111 111.
• Draw up 6 mL ultrapure mercury slowly and carefully using syringe 111 111.
3 Add mercury to MME
• Lower syringe needle 112 112 into the top opening of the MME 38 38 between
sealing ring 106 106 and sealing needle 97 97.
• Expel mercury slowly and carefully from the syringe to allow it to flow into
the Hg reservoir 103 103.
3.4.3 Mounting the capillary
The glass capillaries 109 109 for the multi-mode electrode 38 38 are supplied separately in
a protective plastic package. After they have been unpacked, avoid any contact
whatsoever with the sensitive capillary tip. The capillary 109 109 is mounted in the MME
filled with mercury as described in section 3.4.2 as follows:
1 Insert retaining nut
• Screw retaining nut 108 108 into screw thread 104 104 until a slight resistance is
noticeable (on no account screw in retaining nut fully!).
2 Insert capillary
• Cut open plastic package containing the glass capillary 109 109 on the side
of the large capillary opening using scissors (do not tear open), leave
capillary in the package.
• Insert glass capillary 109 109 directly from its protective plastic package
through the retaining nut 108 108 into the sealing ring 106 106 and push in as far
as it will go.
3 Tighten retaining nut
• Firmly tighten retaining nut 108 108 by hand (do not use a tool). The glass
capillary 109 109 should then be centered in the opening of the retaining nut
108 108.
• If this is not the case, undo retaining nut 108 108 by one full turn and then
retighten by hand. When tightening, move glass capillary 109 109 in a circle
so that it is centered in the feedthrough of the retaining nut 108 108.