Owner manual

3.9 Connection of 685 Dosimats

746 VA Trace Analyzer / 747 VA Stand

3-35

3.9.3 Tubing connection for addition of auxiliary solutions

The 4-way microtip 4747 is not suited for the addition of auxiliary solutions in the mL-

range into the measuring vessel of the 747 VA Stand. For the addition of a first aux-

iliary solution we recommend the use of the following accessories:

• • 1 ×× 6.1819.000 PTFE tube, length L = 77 mm, i.d. = 0.8 mm

• • 2 ×× 6.1805.100 FEP tubing, length L = 40 cm, i.d. = 2 mm

• • 1 ×× 6.1808.000 Coupling

To install these accessories and ready the 685 Dosimat for automatic dispensing,

proceed as follows:

Mount Exchange unit on 685 Dosimat

• Procedure, see section 2 of 685 Instructions for Use.

Insert PTFE tube in 747 VA Stand

• Cut 6.1819.000 PTFE tube (optionally available) to a length of ca. 30 mm

(the tip of the tube should never be immersed into the solution).

• Remove dummy stopper 4242 and insert PTFE tube from above in the

opening 7878 of the measuring head 4141 (see Fig. 9).

Connect FEP tubing to Exchange unit

• Screw 6.1805.100 FEP tubing (optionally available) into opening 7878.

• Screw a 1808.000 Coupling (accessory of 747 VA Stand) to the other end

of the 6.1805.100 FEP tubing and insert this in a slot of the tubing holder

at the rear of the 747 VA Stand.

• Unscrew the 6.1543.050 Burette tip from the 6.1805.100 FEP tubing

attached to the connection 2 of the Exchange unit (see section 3.9.2).

• Screw the other end of the 6.1805.100 FEP tubing attached to the Ex-

change unit to the 6.1808.000 Coupling just inserted in the tubing holder

of the 747 VA Stand.

Initialize Dosimat(s)

• Switch on 746 VA Trace Analyzer using the mains switch 1111.

• Select dialog page "DOSIMATS".

• Set parameter V.init to 0.00 mL.

• Set parameter V.tube in to 1.7 mL.

• Set parameter V.tube out to 3.0 mL.

• Press softkey <Prime all> for initializing all attached Dosimats or select

desired Dosimat with the cursor keys and press softkey <Prime Dosimat>:

The burette cylinder is filled and excess solution is expelled to the meas-

uring vessel. With standard accessories, all tubings to the measuring

vessel will have been filled at the end of the initializing procedure.

• Start the initializing procedure a second time by pressing the softkey

<Prime all> or <Prime Dosimat> again.

• Start the initializing procedure a third time by pressing the softkey <Prime

all> or <Prime Dosimat> again.