Metrohm 757 VA Computrace User Manual

Page 22

3 Installation

757 VA Computrace – Hardware

66 Threaded opening

for FEP tubing 68 (6.1805.180); optional

waste solution lead-off

67 Threaded opening

for FEP tubing 34 (6.1805.090, already

permanently attached); optional waste

solution supply from gas wash bottle to

waste

5 Install reference electrode

• Insert reference electrode 22 in opening 58.
• Attach electrode cable 27 (RE) to reference electrode 22: push cable lug

under the screw and then tighten screw firmly.

• Turn reference electrode 22 so that the electrode cable 27 points to the

rear and not to the side (in the latter position it may become kinked and

damaged when cover 1 is closed).

6 Install auxiliary electrode

• Insert auxiliary electrode 39 (6.0343.000 Pt auxiliary electrode or GC

auxiliary electrode, see section 3.6) in opening 51.

• Attach electrode cable 37) (AE) to auxiliary electrode 39: push cable lug

under the screw and then 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).

7 Install MME or dummy stopper

in operation with MME:
• Carefully insert multi-mode electrode 17 (6.1246.020) in opening 55 (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 30 (6.1805.180) for inert gas supply into connection 72

of the MME 17.

• Screw FEP tubing 38 (6.1805.180) for inert gas supply into connection 73

of the MME 17.

• Attach electrode cable 16 (WE) to screw connection 89 of the MME 17:

push cable lug under the screw and then tighten screw firmly.

in operation with RDE (option):
• Insert stopper 98 (6.2709.040, option) into opening 55 as far as it will go

so that the two blind holes point to the rear of the stand.

• Screw FEP tubing 30 (6.1805.180) into upper hole of stopper 98.
• Screw FEP tubing 38 (6.1805.180) into lower hole of stopper 98.

8 Install measuring vessel

• Tilt back measuring head arm 19.
• Slide measuring vessel 6 into holder 3 from the front and fill with analyte

solution or dist. H

O (storage solution) until the tips of the MME and the

reference electrode are immersed in the liquid.

• Lower measuring head arm 19 and cover 1.