Metrohm 789 Robotic Sample Processor XL - Manual (Page 114)

3.8 Dosing and liquid handling
106 Metrohm Sample Processor, Operation
3.8.8 Preparing the Dosing unit
The Dosing unit must first be prepared, i.e. the filling tubing and pipet-
ting tubing must be rinsed and completely filled. The cylinder contents
must then be ejected.
Command sequence:
MOVE 1 : ext.1
LIFT: 1 : work mm
DOS: 1.1 : prepar. mL
DOS: 1.1 : EndVol mL
DOS: 1.1 : compen. mL
11
Important!
Eject the cylinder con-
tents
This step should be carried out before every sample series involving pi-
petting. Before each pipetting process the Dosing unit cylinder contents
must be completely ejected. This is the only way to achieve reproduci-
ble, accurate pipetting.
The titration cell can then be aspirated, rinsed and prepared with fresh
solvent.
3.8.9 Pipetting
The pipetting procedure takes place in five steps:
• Ejection of cylinder contents (see above) and formation of separat-
ing bubble
• Move to sample
• Aspirate / Measure out sample
• Move to target
• Eject sample