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 multichannel air-displacement pipette liquid-end assembly having a modular construction, which enables individual components to be easily replaced when they become contaminated or worn. The modular liquid-end assembly also enables selected piston and cylinder components to be selectively removed so that any one of a number of predetermined multichannel pipetting configurations can be employed. Additionally, the modular liquid-end assembly preferably comprises an ejector for providing low-friction mechanical advantage in order to facilitate dislodging spent tips.

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: An enclosed pipette tip rack utilizing a container having a bottom and a side portion connected to the bottom which extends upwardly and terminates in a top. A tray is supported by the container and holds at least one pipette tip such that a portion of the pipette tip lies within the container. A cover is also included and is supported by the container adjacent the tray. The container and cover are vented to the ambient environment.

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 liquid chromatography column apparatus which utilizes sorbent packing material in a tube having a first end portion and a second end portion. The first end portion of the tube includes a plug having a passage therethrough. The plug fits in the tube adjacent the packing material and is movable within the tube. An end fitting is also employed adjacent the plug. The end fitting has a passage therethrough which communicates with the passage of the plug. A seal is used inside the tube between the tube and the end fitting. The second end portion of the tube is enclosed and also includes a passage from the interior to the exterior of the tube. A manually actuable gear mechanism is incorporated in the end fitting of the first end portion of the tube for facilitating application of axial force to the packing material, thereby compressing the packing material so as to eliminate voids and channels in the packing material. Other features are also disclosed.

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 chromatography column apparatus which utilizes sorbant material in a tube which has a first and second end portion. The first end portion of the tube includes a plug having a passage through the same. The plug fits in the same, adjacent the sorbant material, and is movable within the tube. An end fitting is also employed which has a portion that is placed within the tube adjacent the plug. The end fitting has a passage therethrough which communicates with the passage of the plug. A seal is used inside the tube between the plug and the end fitting. The end fitting and plug are held together. The second end portion of the tube is enclosed and also includes a passage from the interior to the exterior of the tube.