3 Installation
757 VA Computrace – Hardware
16
3.2.4
Equipping the measuring head
The fixtures inserted in the openings and connections of the measuring head
20
in
the 757 VA Computrace Stand depend on the working electrode selected (MME or
DME) (see
Fig. 6
). The fully equipped measuring head for operation with a multi-
mode electrode is illustrated in
section 2
(
Figs 3 and 4
), that for operation with a ro-
tating disk electrode in
section 3.4
(
Fig. 12
).
When equipping the measuring head for the first time, the best procedure is as fol-
lows:
1 Preparations
•
Prepare multi-mode electrode MME
17
(details, see
section 3.3
) or rotat-
ing disk electrode RDE (details, see
section 3.4
) for operation.
•
Prepare reference electrode
22
(details, see
section 3.5
) for operation.
•
Tilt back cover
1
of measuring head arm.
2 Insert dummy stoppers
•
Screw dummy stopper
41
(6.1446.040) into opening
52
.
•
Screw dummy stopper
40
(6.1446.040) into opening
53
.
3 Insert 4-way microtip (option)
The 6.1824.000 4-way microtip has to be installed if 765 Dosimats are used
for automatic solution addition. Proceed as follows:
•
Remove stopper from nipple
23
and insert 4-way microtip
26
into nipple
23
as far as it will go.
•
Tighten nipple
23
using a 6.2739.010 Wrench until the 4-way microtip
26
can no longer move.
•
Pull the 4 lengths of PTFE tubing of the 4-way microtip
26
in succession
from above through the opening
65
(connection of 665 or 765 Dosimat,
see
section 3.8
).
4 Install stirrer or RDE
in operation with MME:
•
Screw stirrer tip
42
to drive shaft
24
(see also
section 3.7
).
•
Insert stirrer in opening
60
as far as it will go.
•
Stretch drive belt
28
(6.1244.020) between drive wheel
31
and drive shaft
24
of the stirrer.
in operation with RDE (option):
•
Screw electrode tip
99
(6.1204.XXX) to drive shaft
100
(6.1246.000)
(see also
section 3.4
).
•
Insert RDE in opening
60
as far as it will go.
•
Stretch drive belt
28
(6.1244.020) between drive wheel
31
and drive shaft
100
of the RDE.
•
Attach electrode cable
16
(WE) to the RDE: push cable lug under the
screw and then tighten screw firmly.
