Owner manual

3 Installation

746 VA Trace Analyzer / 747 VA Stand

3-18

3.4.4 Filling the capillary without vacuum

The glass capillary 109109 can normally be filled with mercury by the method de-

scribed here without vacuum. However, if difficulties regarding stability or repro-

ducibility arise with a capillary filled in this manner, try to fill the capillaries by the al-

ternative method with vacuum (section 3.4.5).

To fill the mounted glass capillary 109109 (section 3.4.3) with Hg without vacuum, pro-

ceed as follows:

Install multi-mode electrode in 747 VA Stand

• With the measuring head arm 4040 tilted back, slide the empty measuring

vessel 2828 into the holder 2626 of the 747 VA Stand and then lower the

measuring head arm 4040.

• Carefully insert multi-mode electrode 3838 in opening 7676 of the measuring

head 4141 (during insertion, the tip of the capillary 109109 must not touch the

measuring head) and push in carefully as far as it will go. Avoid water

drops touch the tip of the capillary.

Connect multi-mode electrode

• Screw FEP tubing 5151 for the inert gas supply into connection 9393 of the

multi-mode electrode 3838.

• Screw FEP tubing 5959 for the inert gas supply into connection 9494 of the

multi-mode electrode 3838.

• Attach electrode cable 3737 (WE) to screw connection 110110 of the multi-

mode electrode 3838: push cable lug under the screw and then tighten

screw firmly.

Fill capillary with mercury

• Switch on 746 VA Trace Analyzer with mains switch 1111 (746 VA Trace

Analyzer and 747 VA Stand must first be installed properly as described

in section 3.2 and section 3.3).

• Select dialog page "STAND" and then switch on the inert gas supply to

the 747 VA Stand by pressing the softkey <Pressure>. This pressurizes

the multi-mode electrode 3838 and the mercury begins to flow slowly out of

the capillary.

• Gently tap the MME with your finger (to remove any air bubbles) and

allow the mercury to flow out of the capillary into the empty measuring

vessel for approx. 2 min.

• Fill measuring vessel 2828 with 10 mL ultrapure water and add 1 drop KCl

solution (in pure water, mercury drops from the capillary only with diffi-

culty).

• Allow mercury to flow out of the capillary for ca. 2 min while checking the

drop formation: The drop time should be ca. 3 s.

Adjusting the sealing needle 9797

• Turn slotted screw 9696 using a suitable coin slowly in a clockwise direction

until the mercury flow stops.

• Open slotted screw 9696 slightly in an anticlockwise direction until the

mercury flow restarts.