Metrohm 797 VA Computrace - Manual (Page 64)

2 Installation
797 VA Computrace / Hardware-Manual 8.797.8001EN
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0.5 ... 1 mm
Pipetting needle adjustment
Adjust 6.1835.040 or 6.1835.050 pipetting needle at the 838 Ad-
vanced Sample Processor to ensure that the lower end of the nee-
dle is positioned max. 0.5 mm above the bottom of the sample
vessel. This is essential to guarantee a complete transfer of the
sample from the sample vessel into the measuring vessel of the
797 VA Computrace Stand. Follow the Instructions for Use 838 for
the definition of the "work position".
2.10.2 System description for a combined system for
Brightener and Suppressor
Electrical connection
Before any instruments are attached to the 797 VA Computrace
Stand, the 797 VA Computrace Stand must be switched off using the
mains switch 14.
Fig. 21: Electrical connection for a combined system with the 838 Ad-
vanced Sample Processor
A 50 mL Dosing Unit filled with VMS is connected to Dosino 1. A 2 mL Dosing Unit
filled with Brightener standard solution is connected to Dosino 2. For Brightener de-
termination, a 2 mL Dosing Unit filled with Suppressor concentrate is connected to
Dosino 3. For Suppressor determination (with "dilution titration technique"), a 2 mL
Dosing Unit is connected to Dosino 3 to suck Suppressor standard solution or sample
from the 838 rack.
Tubing connections
Below, the tubing connections for Suppressor determination with 11 mL sample ves-
sels and Brightener determination with 50 mL sample vessels (and MLAT) are de-
scribed.