CAVRO XP 3000 - Setting Up the XP 3000 for Your Application; Glossary

Setting Up the XP3000 for Your Application 4-1
4 - Setting Up the XP 3000 for Your Application
The XP 3000 is capable of providing precision pumping in a wide variety of hardware
and fluid systems. The interplay of fluid viscosity, aspiration and dispense speeds, and
system geometry [syringe size, tubing inner diameter (I.D.), and valve I.D.] determines
the behavior of the XP 3000 in a particular application. Following is a description of the
hardware, fluid, and pump control parameters to be evaluated and optimized in managing
these interdependencies for optimal pump performance.
Glossary
air gap
A small volume of air at the end of the output tubing or sandwiched between two
fluids in the pump system tubing. Air gaps may be created by aspirating air
(programmed air gaps) or by the spring action of the fluid system (inertial air gaps).
aspirate/dispense tubing
Connects the valve output port (1/4-28 thread or M6 fitting) to a sample source and
destination. To ensure good breakoff, aspirate/dispense tubing tends to have a
smaller I.D. than reagent tubing, and a necked-down or tapered end.
backlash
Mechanical play in the syringe drive created by accumulated mechanical clearances.
To maintain accuracy and precision when the syringe drive changes direction, the XP
3000 incorporates programmable backlash compensation.
backpressure
The pressure which must be exceeded to move fluid through tubing. Backpressure is
created by a combination of fluid inertia and friction.
breakoff
Describes how the last droplet of fluid exits the end of the output tubing following a
dispense. Rapid or sharp breakoff means that the droplet exits cleanly with high
inertia.
breakup
Undesired air gaps created by overly rapid aspiration.