http://www.parker.com/ppf
Page 9
FIGURE 2
CHARACTERISTICS OF THE PRESSURE
EJECTION SYSTEM
The diameter of the droplet ejected in air was
measured with an ocular micrometer in a dissecting
microscope. The volume was calculated for
droplets formed by varying pressure or pulse
duration parameters. The following graphs
demonstrate that each pipette can be calibrated by
varying these two major determinants of the
volume ejected.
FIGURE 2A: LINEARITY OF VOLUME
EJECTED WITH VAYRING PULSE
DURATION AT CONSTANT PRESSURE
The X-intercept (15 MSEC) represents the
mechanical lag time of the particular solenoid
valve.
FIGURE 2B: LINEARITY OF VOLUME
EJECTED WITH VARYING PRESSURE AT
CONSTANT PULSE, DURATION
The X-intercept (7.5PSI) represents the minimum
pressure necessary for ejection and is a characteristic
of a particular pipette
FIGURE 2C: LINEARITY OF THE AMOUNT
OF AN H3 STANDARD WITH VARIOUS
EJECTED VOLUMES
The points of this graph are highly correlated (R=.97)
with the independently determined specific activity
(6.5 x 106 CPM/mL) of the radioactive solution.
