Abstract: A liquid microdispenser consisting of a barrel with a snap-on capillary dispensing tube tip at one end containing a dispensing plunger adjustably attached to a tubular operating shaft slidably extending through a flanged bushing threaded into the other end of the barrel. A coiled spring in the barrel bears between an abutment bushing secured in the bottom end of the barrel and an abutment bushing secured on the tubular operating shaft. The plunger is in the form of a rod which is adjustably connected to the operating shaft by a set screw, and the barrel has an aperture providing access to the set screw. The abutment bushing at the bottom end of the barrel is formed at its distal end to accept the snap-on capillary tip for positioning by exerting a force thereon directed along the axis of the barrel. A bushing is secured to the top end of the operating shaft, and a headed cover screw member is threadedly engaged in the last-named bushing.

Abstract: A liquid dispensing burette adapted to be mounted on the top of a reagent bottle or container and having inlet and outlet conduits provided with ball check valves in communication with an upstanding burette barrel containing a plunger. The barrel has a volumetric scale and a shield member is secured to the top of the plunger and extends downwardly over the barrel. The shield member has a large window aperture for viewing the scale and has a depending vertical rod fixed therein adjacent the window aperture. A magnifying indicator is adjustably mounted on the rod and overlies the scale, and has a set screw projecting through the window aperture for adjusting the vertical indicator relative to the scale, for setting the volume to be dispensed. The magnifying indicator is engageable with a stop member at the top of the barrel to limit liquid intake produced by upward extension of the plunger in accordance with the set volume.

Abstract: An automatic dilutor consisting of an upstanding calibrated diluent barrel with a lower intake portion adapted to be supported in a diluent container and having an intake check valve. A main diluent plunger is provided in the barrel and develops suction when moved upwardly. The plunger has an enlarged top operating portion with a depending diluent-metering rod on which a diluent indicating lens is adjustably mounted, being engageable with a top flange on the barrel to limit extension of the plunger in accordance with the desired amount of diluent to be dispensed. A branch conduit connects the diluent barrel through another check valve with an upstanding calibrated reagent-aspirating barrel having an outlet conduit connected to its bottom portion.