3 Installation
757 VA Computrace – Hardware
46
max. 0.5 mm
3.9.2 Tubing
connections
For operation of the 757 VA Computrace Stand with 813 Compact Autosampler and
772 Pump Units, the accessories and tubing connections must be installed accord-
ing to
Fig. 16
. Proceed as follows:
1 Install accessories at 757 VA Computrace Stand
•
Instead of the 6.1415.210 measuring vessel, install the 6.1456.210 meas-
uring vessel at the 757 VA Computrace Stand.
•
Cut PFTE tube
43
(6.1819.010) inserted in opening
67
of the measuring
head
20
to a length of
max. 30 mm
(see
Fig. 6
and
17
).
•
Cut PFTE tube
45
(6.1819.010) inserted in opening
66
of the measuring
head
20
to a length of
max. 20 mm
.
•
Cut PFTE tube
120
(6.1819.010) to a length of
max. 20 mm
and insert
from above in opening
53
of the measuring head
20
.
•
Cut the bottom end of PFTE tube
121
(6.1819.010) diagonally and insert
from above in opening
52
of the measuring head
20
. To ensure that the
solution is siphoned off as completely as possible, the end of the tube
must be located in the deepest part of the 6.1456.210 measuring vessel
(left rear when viewed from front).
•
Screw FEP tubing
118
(6.1805.180) into threaded openings
52
and
66
.
•
Screw FEP tubing
119
(6.1805.100) into threaded opening
53
of the
measuring head
20
. Screw a 6.1808.000 tubing coupling to the other end
of FEP tubing
119
and insert the coupling in a slot of the tubing holder at
the rear of the 757 VA Computrace Stand.
2 Connect 813 Compact Autosampler
•
Install accessories at 813 Compact Auto-
sampler (see
Instructions for Use 813
).
•
Adjust 6.1835.030 Pipetting needle at the
757 Compact Autosampler to ensure that
the lower end of the needle is positioned
max. 0.5 mm above the bottom of the
sample vessel (see
Fig. 18
). This is essen-
tial to guarantee a complete transfer of the
sample from the sample vessel into the
measuring vessel of the 757 VA Com-
putrace Stand.
•
Insert 6.1822.410 transfer tubing connected
to 6.1826.020 pump tubing from above into
opening
57
of the measuring head
20
at
the 757 VA Computrace Stand (see
Fig. 6
)
and fix it by screwing the nipple.
Fig. 18: Adjusting the
pipetting needle
