Metrohm 746 VA Trace Analyzer User Manual
Page 61
3 Installation
746 VA Trace Analyzer / 747 VA Stand
3-34
3.9.2
Tubing connection for addition of standard solutions
For the addition of standard solutions in the
µ
L-range into the measuring vessel of
the 747 VA Stand the 4-way microtip 47
47 (6.1824.000) should be used. It is fitted
with 4 lengths of PTFE tubing with connection nipples for direct attachment to the
Exchange unit of the 685 Dosimat. To ready the 685 Dosimat for automatic dis-
pensing, proceed as follows:
1 Mount Exchange unit on 685 Dosimat
•
Procedure, see section 2 of 685 Instructions for Use.
2 Insert 4-way microtip in 747 VA Stand (see section 3.3.2)
•
Remove stopper from nipple 44
44 and insert 4-way microtip 47
47 into nipple
44
44 as far as it will go (see Figs 7 and 9).
•
Tighten nipple 44
44 using a 6.2739.000 Wrench (accessory of 6.3014.XXX
Exchange unit) so that the 4-way microtip 47
47 can no longer move.
•
Pull the 4 lengths of PTFE tubing of the 4-way microtip 47
47 in succession
from above through the opening 86
86.
3 Connect PTFE tubing to Exchange unit
•
Unscrew the attached 6.1805.100 FEP Tubing
(L = 40 cm) from connection 2 (connection for burette
tip) of the flat stopcock on the Exchange unit mounted
on the Dosimat.
•
Screw connection nipple of the PTFE tubing of the
4-way microtip 47
47 onto connection 2 of the flat stop-
cock on the Exchange unit mounted on the Dosimat.
2
4 Close unused PTFE tubings
•
Screw a 6.1808.000 Coupling (accessory of 747 VA Stand) on each
unused PTFE tubing of the 4-way microtip 47
47.
•
Screw a 6.1446.040 Dummy stopper (accessory of 747 VA Stand) on
each 6.1808.000 Coupling.
5 Initialize Dosimat(s)
•
Switch on 746 VA Trace Analyzer using the mains switch 11
11.
•
Select dialog page "DOSIMATS".
•
If volumes
≤
50
µ
L should be dispensed, set parameter
V.init
to
0.05 mL
.
•
Set parameter
V.tube in
to
1.7 mL
.
•
Set parameter
V.tube out
to
0.2 mL
.
•
Press
for initializing all attached Dosimats or select desired
Dosimat with the cursor keys <ç> or <è> and press
mat>
: The burette cylinder is filled and excess solution is expelled to the
measuring vessel. With standard accessories, all tubings to the measur-
ing vessel will have been filled at the end of the initializing procedure.
•
Start the initializing procedure a second time by pressing the softkey
or
again.
•
Start the initializing procedure a third time by pressing the softkey
all>
or
again.