Abstract: A pipette for use with a pipette tip to aspirate and dispense a quantity of liquid, comprising a housing, a pipette tip mounting shaft extending from the housing to receive a pipette tip, a pipette tip ejector mechanism for ejecting the pipette tip from the mounting shaft, energy storage means, means for storing energy in the energy storage means and means for releasing energy from the energy storage means to assist the tip ejector mechanism in the ejecting of the pipette tip from the mounting shaft.

Abstract: A volume adjustable manual pipette having a hand-holdable housing supporting (i) an electronic digital display and associated position sensing and control circuitry, (ii) a plunger unit and (iii) a quick set volume adjustment mechanism for simultaneously controlling the volume setting of the pipette and the electronic display, the quick set volume adjustment mechanism comprising a pipette volume setting member for limiting upward movement of the plunger unit within the housing to define the volume setting for the pipette and the volume setting member being supported for axial movement on the plunger unit and releasably secured relative to the housing by a pipette user operable locking mechanism. When released from the housing, the volume setting member is axially moveable on and with the plunger unit to quickly set the volume for the pipette.

Abstract: A manual pipette including a delayed action home position latch for engaging only after the plunger unit of the pipette has moved downward through its home position to thereafter releasably connect a moveable bottom stop member to the plunger unit to move therewith and upon an upward return of the plunger unit by the pipette's return spring to engage a home position stop to releasably lock the plunger unit in its home position without any downward force being exerted by the pipette user on the plunger unit.

Abstract: A plurality of large maximized internal volume freely nestable pipette tips for mounting in a standard pipette tip rack or refill pack including a horizontally extending pipette tip support having a plurality of through holes arranged in an array, each hole having a center which is spaced a distance "s" from centers of immediately adjacent through holes, each pipette tip having a substantially cylindrical proximal portion and an elongated generally conical distal portion coaxial with and joined to its proximal portion adjacent a downward facing outwardly extending shoulder and including at a distal end of the tip a relatively small orifice for receiving and dispensing fluid into and from the pipette tip upon operation of a pipette to which the pipette tip is mounted, the proximal portion of each pipette tip having an outer diameter equal to or slightly less than "s" and a slightly conical inner surface for tightly receiving and releasably attaching to a pipette tip mounting shaft of a large volume pipette and

Abstract: A refill pack for storing and dispensing pipette tips into a tip rack, comprising a support plate with an array of holes containing disposable pipette tips arranged in an organized array and a carrier for hand positioning the support plate over the tip rack for release of the array of pipette tips into the tip rack.

Abstract: A refill pack of light weight low mass material containing an array of replacement pipette tips for a reusable tip rack. The refill pack comprises a support plate with an array of holes containing pipette tips arranged in an organized manner and including a skirt-like guide for centering and guiding the support plate onto the tip rack with distal end portions of the pipette tips aligned with and vertically entering corresponding holes in an organizing tray in the tip rack.

Abstract: A manual pipette including user controllable latch and trigger mechanisms for releasably locking the plunger of the pipette in a "home" position ready for immersion of the pipette tip in a fluid to be drawn into the tip and further including a user controllable velocity governor for regulating the rate of plunger return from the "home" position to a first or upper stop position in drawing the fluid into the tip.

Abstract: A method and accompanying apparatus for automatically extending the linear dynamic absorbance range of absorbance detectors including multi-lightpath flow cells. The absorbance of a reference beam in a relatively short reference path is multiplied by a ratio of the absorbance of a sample beam in a relatively long sample path to the reference path absorbance in developing a relative absorbance for the sample path beyond its linear dynamic range.

Abstract: A compact high performance absorbance detector including a flashlamp light source and folded optics system with ruled grating reflecting beam splitter for minimizing flash to flash angular pattern and spectral variations of the flashlamp.

Abstract: A fluid sample flow cell characterized by a circumferentially uniform radial fluid flow into an entry port to and/or from an exit port from a fluid passageway through the body of the cell.

Abstract: A fluid sample flow cell including a high pressure fluid tight circumferential edge seal for a window in the body of the flow cell.

Abstract: A hand held self-contained automated pipette for portable operation having an electrically operated digital linear actuator. The actuator preferably includes a stepper motor driving a rotor. A threaded screw is coaxially positioned within the rotor and is connected to an actuator shaft having elongate grooves slidable in a guide for preventing shaft rotation so that precise linear motion is imparted to the shaft. A pipetting displacement assembly having one of various sizes is removably attached for actuation by a common actuator including programmed movement of a displacing piston in a displacement cylinder to optimize air interface volume, neutralize variations in vacuum pipette effects, and provide an accommodated stroke and readout for improved accuracy while pipetting and/or titrating different ranges of volumes. Upon calibration the piston undertakes immediate excursion to an end of travel limit and after motor slippage is retracted to a home position.

Abstract: A system for depassivating a passivated lithium battery in a battery powered microprocessor controlled device by successively and momentarily drawing current from the passivated battery after a turn on of the device while monitoring the power delivery condition of the battery under a load condition until salt crystals on an electrode of the battery are dissipated and the battery is returned to a useful power delivery condition or until a predetermined period of time has elapsed without the battery returning to the useful power delivery condition, whichever is sooner.

Abstract: A fluid pump for use in high performance liquid chromatography having a piston movable in a chamber for drawing fluid into, pressurizing, and delivering the pressurized fluid from the chamber. A pressure transducer in the chamber derives a pressure output signal indicative of chamber pressure. Means is provided for correcting offset errors in the pressure output signal.

Abstract: A dashpot piston mounted in a closed chamber is coupled by an axially movable shaft to a pipette piston to regulate return movement of the pipette piston within a pipette cylinder to draw fluid into the cylinder. The dashpot shaft is movable within limits relative to the dashpot piston to accommodate a blow-out of residual fluid from the pipette by the shaft driving the pipette piston beyond a home position to blow residual fluid from the pipette cylinder. An air inlet port in the bottom of the chamber allows air to be drawn into the chamber with upward movement of the dashpot piston while a valve adjacent to the air inlet port opens in response to downward movement of the dashpot piston to exit air from the chamber. Control of the relative sizes of the air inlet port and valve outlet regulates the relative rates of upward and downward piston movement in the cylinder.

Abstract: A disposable pipette tip member having three inner coaxial annular sealing bands spaced axially from an open proximal end for receiving a conical pipette tip mounting shaft. The first two sealing bands and adjacent valley regions of the tip member are relatively resilient and are shaped such that the two sealing bands simultaneously engage, guide and laterally support the pipette shaft as it enters the tip member to form annular fluid-tight seals with the shaft. The third band is relatively rigid and upon engagement with the shaft, forms a third annular fluid-tight seal and a controllable stop for the shaft such that the tip member is seated on the shaft adjacent the pipette tip ejector mechanism.

Abstract: A hand held self-contained automated pipette for portable operation having an electrically operated digital linear actuator. The actuator preferably includes a stepper motor driving a rotor. A threaded screw is coaxially positioned within the rotor and is connected to an actuator shaft having elongate grooves slidable in a guide for preventing shaft rotation so that precise linear motion is imparted to the shaft. A pipetting displacement assembly having one of various sizes is removably attached for actuation by a common actuator including programmed movement of a displacing piston in a displacement cylinder to optimize air interface volume, neutralize variations in vacuum pipette effects, and provide an accommodated stroke and readout for improved accuracy while pipetting and/or titrating different ranges of volumes. A control circuit is provided so that the back EMF of the stepper motor coils is recirculated when power is duty-cycled off for power conservation.

Abstract: A pipette is disclosed which includes a pipette body, a tip locking mechanism, and a disposable pipette tip. The pipette body has a plunger which reciprocates into and out of an interior air filled chamber. This air forces a measured amount of liquid into or out of the tip. After pipetting, an over-stroke of the plunger discharges a blast of air to assure discharge of all the fluid. In one embodiment, a further over-stroke unlocks a mechanism holding the shell in place and actuates tip disposal and replacement. The shell surrounding the pipette body is depressed by the plunger shaft. Fingers formed from the lower end of the shell are pushed outward by cam action with the pipette body. As the fingers spread, the tip falls free. A replacement tip is then attached. The fingers also define a funnel which guides the replacement tip on to the point where it snaps into position.

Abstract: A fluid pump mechanism for delivering a smooth output of fluids to a system utilizing at least one piston in a chamber reciprocative therewithin. The piston has strokes that fill and empty the chamber in conjunction with the action of valve means located at the inlet and outlet of the chamber. Motive means causes reciprocation of the piston within the chamber. Control means is also included for minimizing the time during the piston cycle in which the piston is not emptying the chamber. The invention's scope also encompasses a pressure metering device for a fluid forcing means motivated by an electrical motor.

Abstract: A fluid pump mechanism for delivering a smooth output of fluids to a system utilizing at least one piston in a chamber reciprocative therewithin. The piston has strokes that fill and empty the chamber in conjunction with the action of valve means located at the inlet and outlet of the chamber. Motive means causes reciprocation of the piston within the chamber. Control means is also included for minimizing the time during the piston cycle in which the piston is not emptying the chamber. The invention's scope also encompasses a pressure metering device for a fluid forcing means motivated by an electrical motor.