Metrohm MVA-20 - Manual (Page 7)

Application Bulletin 402/1 e
Installation instruction for MVA-20
3.5.2. Rack
Rack name 6.2041.490
Shift rate 20 °/s
3.5.3. Rack data
Rack parameters
Beaker radius samples off mm
Beaker sensor off
Rack offset 0 °
Lift positions – Tower 1
Work position User
defined, see
3.5.4
mm
Rinse position 0 mm
Shift position 0 mm
Special position 0 mm
Lift positions – Tower 2
Work position Not available
Rinse position Not available
Shift position Not available
Special position Not available
Special beakers
Not used
3.5.4. Needle adjustment
The work position of the pipetting needle 6.1835.050 has to
be adjusted in a way that the lower end of the needle is
positioned max. 1 mm above the bottom of the sample vial.
This is essential to guarantee a complete transfer of the
sample from the sample vial on the rack of the 919 IC
Autosampler plus into the measuring vessel of the 894
Professional CVS.
Fig. 9: Needle adjustment
Procedure to adjust the needle position in viva
1. Insert an empty sample vial to one of the sample
positions on the rack (position 1 to 28).
2. Click on the Manual symbol.
3. Select Tower 1 (Sample changers – 919 IC
Autosampler plus 1).
4. Open tab «Move».
5. Enter the position of the empty sample vial in the field
«Target position».
6. Click Start to move the needle to the chosen rack
position.
7. Enter 125 mm in the field «Target position» in the
section «Lift position».
8. Click Start to lower the needle to the chosen target
position. For the exact positioning of the needle as
shown in «Fig. 9», use the arrow up and down buttons
to adjust the needle position stepwise.
9. Once the needle is properly adjusted select the tab
«Assign position».
0.5 … 1 mm
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