Drummond Scientific Company

Nicholas M DiTrolio

Eric L Canfield

A rugged, all-electronic fluid dispensing system for use with pipettes or in other contexts indirectly measures fluid flow by using a non-linear system model to correlate vacuum existing at the top of a column of suspended fluid. Non-contact operation is provided to eliminate the need for contact-type closed-loop fluid flow sensing and associated potential cross-contamination risks. In one particular exemplary non-limiting illustrative implementation, an electronic controller within a gun-shaped, cordless self-contained pipetter housing dynamically calculates valve opening time based on a non-linear equation. Calibration is used to derive equation constants, and column vacuum pressure before the valve is opened is used as the independent variable to derive a valve opening time that will result in accurate dispensing of a desired programmed fluid quantity. Repetitive automatic dispensing with accuracies greater than 1% are possible within the context of a relatively inexpensive portable pipette or device without the need for mechanically-complex positive displacement arrangements.

Automatic precision non-contact open-loop fluid dispensing

A pipette dispenser unit having a hand-held pipette dispenser having a pipette connector and a handle, a source of positive and negative air pressure in fluid connection with said pipette connector, and a foot-operated controller for regulating the flow of air between said air pressure source and said pipette connector. A method of metering fluid through a pipette by connecting the pipette to the pipette dispenser, holding the dispenser with one hand, and controlling fluid flow through the pipette by operating the controller with at least one foot.

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Havertown, PA, United States of America

Nicholas M DiTrolio