Metrohm 746 VA Trace Analyzer - Manual (Page 37)

3 Installation
746 VA Trace Analyzer / 747 VA Stand
3-10
7 Install MME or dummy stopper
in operation with MME:
• Carefully insert multi-mode electrode 38 38 (6.1246.020) in opening 76 76 (the
underside of the capillary must not touch the measuring head during in-
sertion) and push in as far as it will go.
• Screw FEP tubing 51 51 (6.1805.180) for inert gas supply into connection 93 93
of the MME 38 38.
• Screw FEP tubing 59 59 (6.1805.180) for inert gas supply into connection 94 94
of the MME 38 38.
• Attach electrode cable 37 37 (WE) to screw connection 110 110 of the MME 38 38:
push cable lug under the screw and then tighten screw firmly.
in operation with RDE (option):
• Insert stopper 119 119 (6.2709.040, option) into opening 76 76 as far as it will go
so that the two blind holes point to the rear of the stand.
• Screw FEP tubing 51 51 (6.1805.180) into upper hole of stopper 119 119.
• Screw FEP tubing 59 59 (6.1805.180) into lower hole of stopper 119 119.
8 Install accessories for rinsing and siphoning off (option)
For rinsing the measuring vessel at the 747 VA Stand manually (dialog
page "STAND") or with the RINSE command, two 700 Dosinos with
50 mL Dosing units must be connected to the 746 VA Trace Analyzer
and initialized acc. to section 3.10.5 and the 6.1456.210 measuring
vessel (option) must be used instead of the 6.1415.210 measuring
vessel.
• Cut PTFE tube 91 91 (6.1819.010) to a length of ca. 30 mm and insert from
above in opening 74 74 of measuring head 41 41 (see Fig. 10).
• Cut the bottom end of PTFE tube 92 92 (6.1819.010) diagonally and insert
from above in opening 73 73 of measuring head 41 41. To ensure that the solu-
tion is siphoned off as completely as possible, the end of the tube must
be located in the deepest part of the 6.1456.210 measuring vessel (left
rear when viewed from front).
• Screw FEP tubing 89 89 (6.1805.180) into the threaded openings 73 73 and 87 87.
• Screw FEP tubing 90 90 (6.1805.100) into threaded opening 74 74 of measur-
ing head 41 41. Screw a 6.1808.000 tubing coupling to the other end of FEP
tubing 90 90 and insert the coupling in a slot of the tubing holder at the rear
of the VA Stand.
9 Install measuring vessel
• Tilt back measuring head arm 40 40.
• Slide measuring vessel 28 28 into holder 26 26 from the front and fill with
analyte solution or dist. H
2
O (storage solution) until the tips of the MME
and the reference electrode are immersed in the liquid.
• Lower measuring head arm 40 40 and cover 24 24.