Abstract: Apparatus and method for obtaining a concentration gradient in a liquid sample analyzer including flowing a first liquid in a stream to fill a conduit, and continuing the flow of the first liquid along the conduit subsequent to the filling step. Combined with these steps is the step of changing the concentration of the first liquid by removing from the stream a predetermined varying volume of the first liquid and adding to the stream a predetermined proportional varying volume of a second liquid. There is also provided a method of serial dilutions of a liquid stream in a conduit by removal of a portion of the stream prior to each diluent addition for the purpose of conserving diluents which may be reagents.

Abstract: A standard, which is of ceramic material and preferably includes alumina, for spectral reflectance for use in near infrared reflectance measurements of constituents of samples, which constituents comprise oil, moisture and protein. The standard reflects electromagnetic radiation in the wavelength range of 1.0 - 2.5 micrometers and exhibits its best optical characteristics in the operational range of 1.4 - 2.4 micrometers.

Abstract: A multichamber cuvette for maintaining in independent and separate condition at least two reactants, one of which may be a sample, until such time that it is desired to mix them for reaction with each other for photometric analysis in the cuvette. At least one of the chambers has a pair of optical quality windows aligned with one another for analysis of the then liquid contents extending between the windows. The cuvette body is of upright construction, defining at least two such chambers laterally of one another, open at the top for filling separately or simultaneously, and interconnected adjacent their lower extremities by a passageway of inverted U shape. The passageway is of an effective height exceeding the highest filling level of each chamber by a distance at least as great as any capillary rise in the passageway beyond such level of the particular liquid in that chamber.

Abstract: Apparatus and method for analyzing successive liquid samples and conserving reagent. The method includes flowing a stream of discrete samples along a conduit from a source, which conduit includes a portion for reacting the successive samples with a reagent and a portion for analyzing the reaction product. It further includes introducing the reagent into the conduit upstream of the reaction portion to form a sample-reagent mixture, identifying the successive samples at the source, and responsive to such identification discontinuing the introduction of the reagent into the conduit and substituting therefore a pilot fluid displacing the mixture at the same flow rate along the reacting and analysis portions of the conduit.

Abstract: Apparatus and method for analyzing liquid sample comprising flowing a stream including a liquid continuously in a conduit, detecting a flow rate characteristic in the conduit and generating a signal in response thereto, and increasing, decreasing or maintaining, unchanged the flow rate of the stream in the conduit in response to the signal, the flow being increased or decreased by the flow into the conduit of another fluid without changing the concentration of the aforementioned liquid. The continuing flow of the liquid may be the flow of a segmented sample-reagent liquid, and the other fluid which is added may be a gas.

Abstract: Method and apparatus for photometric analysis of sample fluids for a constituent of interest. There is provided a method of sample analysis comprising the steps of locating the sample fluid in a cell having an axis, directing a ray of light through the sample and the sample-cell interface at an angle to said axis, totally internally reflecting said light ray passed through the interface to be redirected across said sample, and detecting the redirected light ray passed through the sample.

Abstract: Apparatus and method, utilizing an ion-selective electrode and a reference electrode, for determining the percentage volume of total particulates in a predetermined volume of a liquid medium or sample having an effective known concentration of a particular ion. The method includes introducing a predetermined volume of a diluent having a known concentration of that ion into the sample, and measuring with the electrodes the concentration of that ion in the diluted sample to indicate the percentage volume of total particulates in the sample. The apparatus and method for such determination are well suited for determining the percentage volume of total cells in a sample of whole blood.

Abstract: Apparatus and method for preparing a smear of a biological fluid substance on a substrate, utilizing a ribbon having relatively small openings in at least one surface thereof which openings are of substantially uniform size and are arranged substantially uniformly both longitudinally and transversely of the ribbon throughout at least a portion of the ribbon. The method includes the steps of supporting the substrate for movement and supporting the ribbon by a support in close proximity to the substrate at a substance-applying station, for a run of the ribbon past a portion of the substrate. Further steps include introducing a relatively small quantity of the aforementioned substance between the aforementioned ribbon surface portion and the substrate at the substance-applying station to spread by capillarity in a direction transversely of the ribbon, and moving the substrate in a direction to smear the substance on the substrate.

Abstract: A method for separating a blood cell portion and a liquid portion of a whole blood sample comprising the steps of contacting over a period of time a substance in the form of a nonparticulate gel mass with the sample, so as to diffuse the liquid portion into the mass, the mass having an effective pore size to exclude the blood cells, and collecting the blood cells remaining after such contact of the sample with the mass. The method may include impregnating the substance of the mass with a selective reagent to react with the liquid portion diffused therein, and furthr include analyzing a reaction product produced within the mass.

Abstract: A fluid sampler which may be held in the hand in the manner of a pencil is provided with an overstroke so that after a plunger is operated with a certain stroke to sample a determinable amount of fluid, the plunger can then be operated with an overstroke to make certain that all fluid is discharged from the sampler. The stroke of the plunger is furthermore adjustable. The sampler is provided with a longitudinally extended portable body provided with a bore extending longitudinally therethrough. A nozzle is provided at one end of the bore within which is a chamber. A plunger is located partly in the chamber and partly in the bore with a piston being operatively associated with the plunger and slidable in the bore. An adjustable control is provided in the bore to adjust the stroke of the piston. A lever is mounted on the body to operate the plunger through the intermediary of the piston whereby fluid may be drawn into or discharged from the aforementioned chamber.

Abstract: New and improved apparatus is provided for the calibration and standardization of the analog output signal level of automated analysis equipment, which level varies as a function of the concentration of the constituent being analyzed. Such apparatus comprises an A/D converter including a dual-slope integrator for translating the output signal level to a time interval which varies as a function of the constituent. Such apparatus further includes means for generating the inverse function of the analytical function, which is applied to linearize and scale the output signal level and to convert such level directly to digital form. Also, provision is made for the calibration and standardization, on an individual basis, of each of a plurality of analytical channels in a multi-channel system.

Abstract: Apparatus and method for photometrically analyzing a constituent of interest in body or other fluids and well suited for kinetic determinations which are temperature-and-time dependent. There is provided a sample holder holding a cuvette supporting a liquid sample and other reactants among which is a trigger reactant to initiate the reaction which is analyzed. The trigger and the other reactants are initially isolated in the cuvette.

Abstract: Method and apparatus for continuously casting metal tubing, utilizing an oscillatable mold, which lends itself to the casting of tubing of relatively large internal diameter. Molten metal is poured directly into the mold having a chilled axial wall structure, and then a starting bar, having at least an annular end portion immersed in the molten metal in the mold, is moved relatively to the mold to withdraw the solidifying cast metal tubing adhering thereto, during oscillation of the mold, the molten metal for such tubing being supplied from the mold. The supply of molten metal in the mold may be replenished by pouring additional molten metal directly into the mold through the annular starting bar without contact of the molten metal with either the starting bar or the solidifying tubing prior to the entry of such molten metal into the mold.

Abstract: Apparatus is described for treating substances carried or affixed to a surface of a continuous substrate, e.g., a ribbon or tape, with successive treating fluids including liquids contained in a series of treating chambers, adjacent chambers being separated by a high surface tension liquid, e.g., mercury. The chambers may be defined by hollow walls having slots located below the level of the treating fluids in the adjacent treating chambers, such slots being dimensioned to allow passage of the tape between the adjacent treating chambers and to prevent dislocation of the high-surface tension liquid, which is located in the hollow walls and serves to wipe excess treating fluid from the tape during passage between the adjacent treating chambers, so as to prevent carryover therebetween.

Abstract: An aspirating probe which has a travel from a lower position in which it is immersed in a liquid in a receptacle to an upper position in which it clears the receptacle, carrying with it in its movement to the upper position a washing device to wash the interior and exterior thereof when in the last-mentioned position.

Abstract: Method and apparatus in an automated sample analysis system for on-line preparation from plural constituents of a reagent for combination with a sample, which includes purification of the reagent prior to exposure of the reagent in a flowing stream to a flowing stream of such sample. For such reagent preparation, the fluid constituents are caused to flow in respective streams which combine in the required volumes in a predetermined sequence to form a resultant stream in which the constituents intermingle and interact. This stream passes through a purifier as it flows toward a confluence with the sample stream, to free the reagent from one or more elements which would interfere with sample analysis.

Abstract: Method and apparatus are provided for processing the successive echo pulses which result from the interrogation of a layered material by energy pulses, and include the direct provision from said echo pulses of the uncompensated coherent echo response of said material to thereby preserve phase information, the provision of the compensated impulse response of said material by modification of said echo response with a non-linear correction function, and the calculation of the RAYLOGRAM of said material from said impulse response. All of the above is accomplished in the complete absence of deconvolution, and said non-linear correction function includes a normalization factor to normalize the impulse response and provision for modifying the latter to compensate for energy pulse attenuation in the material to render it more accurate by satisfying the known boundary conditions of said layered material.