Air Displacement Pipette

The liquid s density influences the size of air cushion e g.

Air displacement pipette.

When enabled the pressure is monitored in the tip. Both pipette types have a piston that moves in a cylinder or capillary. These liquids tend to vaporize in the tip which raises the air pressure resulting in liquid dripping from the tip. In air displacement pipettes a certain volume of air remains between the piston and the liquid.

When using positive displacement pipettes there is no elastic air space to expand or contract so the aspiration force remains constant unaffected by the physical properties of the sample. In positive displacement pipetting the piston is in direct contact with the liquid. Getting down to the basics an air displacement pipette is a common laboratory tool used to handle a measured volume of liquid between 1 µl to 1000 µl 1 ml. A vacuum is generated by the vertical travel of a metal or ceramic piston within an airtight sleeve.

As with any gas the air cushion varies according to the characteristics of liquids as well as in part by lab or. These pipettes operate by piston driven air displacement. No air cushion therefore no problem. Too low too high volume is pipetted.

However conditions such as temperature atmospheric pressure as well as the specific gravity and viscosity of the solution may have an effect on the performance of air displacement pipettes. Laboratory pipettes can function either via air displacement or by positive displacement principles. Adjust pipette to liquid becomes fixed volume pipette for adjusted volume. Due to its high accuracy this laboratory tool is commonly used in standard pipetting applications.

Acids bases and solvents are the worst enemies of any air displacement pipette. Zeus is equipped with anti droplet control adc. As the piston moves upward driven by the depression of the plunger a vacuum is created in the space left vacant by the piston. Air displacement pipette used for standard pipetting applications is highly accurate.

Volatile liquids like acetone and methanol can be extremely difficult to pipette using air displacement.