Abstract: A plate-like structure comprising a liquid flow path formed in one face thereof, a thin ductile seal-forming coating on the face of the structure which forms the flow path. The structure finds many utilities, most advantageously in constructing a novel valve wherein the disk is flexible and adapted for flexing a central face portion thereof against a conduit, thereby sealing said conduit.
Abstract: Novel photometric apparatus advantageously having a conical shaped flow-cell comprising a light source proximate the narrow end and a photosensitive detector at the wider end of the cell. The flow-cell adequately compensates for a lens effect that has been discovered to be a substantial factor in electro-magnetic energy absorption studies on liquid streams.
Abstract: A compact pumping system especially useful in liquid chromatography wherein comprising a liquid path which is fully flushed on each stroke of a pump, a pump which provides substantially pulse-free flow, a pressure-sensor integrated into said flow path and operably connected to the control circuit of a bifilar stepping motor. This circuit is so designed that the driving current applied to the motor is only that required to pump the liquid. The avoiding of heat associated with a greater current is particularly important in forming a compact package of motor and pump for use in liquid chromatography.
February 3, 1975
Date of Patent:
May 25, 1976
Waters Associates, Incorporated
Louis Abrahams, Burleigh M. Hutchins, Jr., James L. Waters