Endress+Hauser Analytik Jena CyBio Well vario, User Manual, Page: 108 / 150

92 Rev B 2022/03
Operation CyBio Well vario
dispensed with additional stroke (5) into a waste box or the reservoir. Since the stroke
length is greater than actually required for the residual volume (D3), the residual volume is
completely dispensed. Finally, the amount of air is dispensed (D4). A volume cycle is com-
pleted by "Motion into zero-position".
A "Move pistons into zero-position" command (6) triggers upward piston motion to their
initial positions, thus excluding the lower freeplay.
This process must be triggered with no liquid present, i.e. the lifter must be in such a posi-
tion that the tips cannot make contact with liquid. Liquid which is aspirated in the process
may result in dosing errors or contamination of pistons.
7.4.2 Aspiration without additional stroke
Fig. 118: Aspiration without additional stroke
Where liquid is aspirated without an additional stroke, it must be dispensed in a single
step, in order to achieve precise results. This cycle must provide for a motion length that is
greater for dispensing (4) than that for aspiration (2). Since the reversal point of piston
motion lies within the motion range that is covered by the pistons for dispensing, no vol-
ume is dispensed on excession of the upper freeplay (3). If dispensing motion covers a
motion length that is greater than actually required for a given nominal volume, the previ-
ously aspirated volume will be completely dispensed from the pipette tip, with subsequent
dispensing of air (D2).
A "Move pistons into zero-position" command (5) triggers upward piston motion to their
initial positions, thus excluding the lower freeplay.
This process must be triggered with no liquid present, i.e. the lifter must be in such a posi-
tion that the tips cannot make contact with liquid. Liquid which is aspirated in the process
may result in dosing errors or contamination of pistons.
1 Zero-position
2 Aspiration
3 Upper freeplay
4 Dispensing with additional stroke
5 Motion to zero-position A1=D1: nominal pipetting volume
D2: Air