Abstract: The liquid chromatographic column (LCC) in liquid chromatography apparatus (LCA) is connected to another fluid flow member, e.g., an injection valve and/or a detector, via a column retainer that comprises a collet with split, tapered distal end that threads into a collet nut having an internal tapered lumen to cause the collet split end to compress about the outside of the liquid chromatographic column so that the retainer assembly may hold the column without damage to it in connected position with the other fluid flow member. The column retainer may include a retainer nut that serves to hold the retainer assembly onto the fluid flow member by threading into a female opening in it.

Abstract: Improved optical systems for liquid chromatographic apparatus comprise flow cells with light transparent portions through which one or more beams of light may be passed through an effluent stream flowing in the cell, one or more light sources on one side of the flow cell to project light through the cell and its contained effluent stream, one or more light limiting apertures positioned on the opposite side of the cell in the paths of the light beams, one or more positive light focusing elements positioned in the path of the light beams from the cell to the apertures to image the center of the cell at the apertures and a light sensor positioned in the path of the light beam on the side of each aperture opposite to its respective light focusing element.Improved methods of chromatographic analysis using the new optical systems are also disclosed.

Abstract: In the analysis of substances by liquid chromatography, samples to be analyzed are introduced into the chromatography column by being loaded into a fluid permeable section in a cartridge, placing the sample loaded section over the inlet end of the column and flowing solvent through such section into the column. The cartridge may be a plate with an opening through it with the ends of the opening covered by permeable membranes or the opening may be packed with porous material. The cartridge may have a plurality of such openings and these may be in the form of a line on a rectangular plate or a circle on a circular plate. The new methods and devices of the invention are particularly useful in micro-scale liquid chromatographic procedures.

Abstract: Disclosed is an oxygen analyzer probe for use in situ in the flue gas stream of a furnace of the type having a housing, a solid electrolytic oxygen sensor adjacent to one end of the housing and first and second noble metal leads connected to the sensor. The present invention includes a terminal block within the housing to which the noble metal leads are releasably connected. At the terminal block intermediate leads of a metal dissimilar to the noble metal lead are connected thereto. Since all connections between dissimilar metals are made at the terminal block and since all such connections are at approximately the same temperature, no unbalanced thermocouples are introduced into the electrical path from the sensor. In one embodiment, the intermediate leads are comprised of a nickel alloy and have sufficient rigidity to form the prongs of a male plug connector which prongs extend from the rear end of the housing.

Abstract: A water pump drive mechanism for an evaporative cooler which includes a blower housing, a blower shaft extending therefrom, a pulley fixed on the shaft, and a water pump; the drive mechanism having an elongated tube mounted on the housing extending from the pump toward the pulley, a drive shaft extending longitudinally of the tube and rotationally mounted thereon having a lower end rotationally engaged with the pump and an upper end adjacent to the pulley, and a friction wheel mounted in the upper end of the drive shaft engaging the pulley for rotational drive of the water pump from the pulley.

Abstract: An improved flowmeter is disclosed which comprises a fixed magnetic ring at one end of a cylindrical tube and a second magnetic ring disposed within the tube adapted to slide freely therein, and being moved by the fluid to be measured. The opposing magnets exert a repulsive force on one another which is balanced by the fluid flow; the position of the movable magnet provides an indication of the quantity of flow.

Abstract: Described is a magnetically coupled pump and an impeller assembly therefor. In a magnetically coupled pump wherein the hub portion of a rotary impeller is inserted within the bore of a hollow cylindrical driven magnet to be rotated by a surrounding annular driving magnet, the hub portion of the impeller is provided with a deformable projection. A tapered wedge is inserted into the bore to deform the projection and to attach the driven magnet to the hub. The tapered wedge is formed of graphite which also performs the function of a bushing upon which the impeller is rotated.

Abstract: The present invention relates to a centrifugal pump assembly in which an impeller is mounted to a motor shaft without the need for precision machining of the shaft and in which the proper spacing is automatically achieved between the impeller and the pump housing. An end of the motor shaft projects toward an impeller chamber in which a rotary impeller is situated. The impeller hub has a bore therein through which a threaded fastening means passes. The threaded fastening means mates with a threaded well in the end of a motor shaft. However, a coil spring which surrounds the fastening means abuts the shaft end and also abuts the impeller hub. The spring biases the impeller away from the wall of the pump housing and toward the interior of the impeller chamber. The spring prevents the impeller from abutting against the housing wall and the bias of the spring may be adjusted to compensate for variations in the shaft length.

Abstract: An apparatus and method for producing a gradient between two eluents. The form or slope characteristics of the gradient may be varied to suit a given application. Apparatus are provided for expanding or compressing the range of the gradient while maintaining its form over a wide range of values. In a preferred embodiment the apparatus include means for controlling the form of the reset gradient in order to avoid detrimental shock to the chromatographic column.

Abstract: An improved container for storing and conditioning both hard and soft contact lenses. A pair of lens-retaining baskets are pivotally mounted within the cap of a fluid-tight container. With the cap removed and inverted, the baskets may be folded outwardly to allow unimpaired access to the lenses therein. The basket lids open in a common direction, providing immediate identification of right and left lens baskets.

Abstract: A controller maintains a constant desired fluid pressure in a fluid load driven by a variable flow fluid pump with a variable speed motor. A set point signal representing desired pressure and a signal from a pressure transducer representing actual pressure are applied to an error amplifier. The resulting error signal is applied through a variable gain stage to the motor control. The variable gain stage includes first and second variable gain amplifiers the first of which has a gain which is controlled inversely to pressure. The second variable gain amplifier has a gain which is controlled in proportion to flow. In this manner, the gain of the controller changes in inverse proportion to the restriction of the fluid load. This makes the performance of the controller independent of changes in the fluid load by keeping the total loop gain constant.

Abstract: A colorimetric analyzer automatically and continuously measures the transmission of light through a sample which has been mixed with reagents. Precise volumes of the sample are repeatedly measured by a siphon tube. Volumes of the reagent are added to the sample at different times in a measuring cycle. The reagent is added at different places in the analyzer so that it is possible for two different time-consuming reactions to proceed simultaneously. The mixed reagent and sample is supplied to a measuring cell which includes a source of light and a photocell. The distance between the source of light and the photocell are adjustable to accommodate analyses of mixtures with widely varying light transmission while providing a full scale output indication. The output of a photocell is applied to a sample and hold circuit during time intervals when the reactions of the reagents with the sample have been completed.

Abstract: An improved spectrophotometer of the non-dispersive absorption type useful for detecting the presence of SO.sub.2 in a gaseous sample, despite the simultaneous presence of NO.sub.2. Ultraviolet light from a commercially-available source impinges upon a fixed phosphor screen which fluoresces to produce ultraviolet radiation at a first wavelength, at which both SO.sub.2 and NO.sub.2 absorb radiation; and at a second wavelength at which absorption by SO.sub.2 is minimal but NO.sub.2 absorption is approximately the same as at the first wavelength. The radiation is directed through a sample chamber having windows which are transversely slidable to effect cleaning without destroying the integrity of the chamber seal, then introduced into an envelope enclosing filters and a pair of photosensors. One photosensor receives light at the second wavelength and produces a signal which reflects the attenuation by NO.sub.2 at that wavelength.