Abstract: Liquid sampling apparatus includes a hollow sample intake tube that has an inlet port adapted to receive sample material to be analyzed, and is mounted on a support for movement about a fixed pivot between a reset position and at least two sample intake positions. Also mounted on the support is manually manipulable drive link structure that carries a slider assembly that receives the intake tube. Track structure on the support guides movement of the link structure to slide the slide member along the intake tube between a reset position in which the inlet port is aligned with a waste receptacle, a first sample in which the inlet port extends forward of the slide assembly for insertion into a sample container, and a second sample in which the inlet port is housed in coupling structure carried by the slider assembly and presented to the operator for connection of a transfer device such as a capillary tube.

Abstract: Blood gas control containing hemoglobin, a pH buffering agent, and a reduced pyridine nucleotide capable of participating in a reaction which reduces methemoglobin to normal hemoglobin.

Abstract: An electrochemical sensor system includes a high impedance ion selective electrode and an electrode test circuit that has an isolation capacitor connected between the output signal lead from the ion selective electrode and a test voltage terminal, and a monitoring circuit connected to respond to the output signal from the electrode. The isolation capacitor is a high quality capacitor and provides a shunt impedance that is much higher than the maximum electrode impedance. A voltage transition at the test voltage terminal is coupled by the isolation capacitor to the output lead and the resulting decay rate of the voltage transition on the output lead is monitored to provide an indication of the quality of the electrode.

Abstract: A replaceable cartridge assembly for use with electrochemical analysis apparatus includes a housing of electrically insulating material that defines an annular electrolyte chamber with coupling structure at one end of the housing and a chamber port at the other end of the housing. A selectively permeable membrane extends across the port in sealing relation thereto. An elongated guide channel within the housing is surrounded by the electrolyte chamber and receives a cooperating connector stem that carries a socket-temperature sensor assembly. A cathode electrode projects coaxially upwardly from the end wall of the guide channel into the stem socket and the lower portion of the cathode electrode extends through the guide channel end wall such that its tip is exposed to the membrane. An anode electrode is disposed in the electrolyte chamber with an external contact surface adjacent the coupling structure.

Abstract: Sample handling apparatus includes a disposable, single use sample vessel that includes reclosable port structure, and coupling structure adjacent said port structure. Cooperating sample transfer structure for detachable connection to the coupling structure of the vessel includes a transfer passage and a port opening probe portion and is movable to a position in which the probe portion opens the reclosable port structure to provide a flow path between the transfer passage and the sample storage vessel. In that position, the vessel and sample transfer structure cooperate to define a sealed chamber that has a flexible, resilient wall.

Abstract: An atomic absorption system comprising a radiation source that emits spectral line radiation characteristic of an element to be analyzed, an analysis region open to passage of the beam of radiation from the source and in which a sample of the substance to be analyzed is atomized, source control means for alternately energizing the source at a first intensity level to provide a radiation output that has a narrow spectral line at a wavelength of an element to be detected and at a higher intensity level to provide a radiation output of broader wavelength with intensity suppression at the wavelength of the narrow spectral line, electronic transducing means for developing an electrical signal corresponding to the sensed radiation intensity of the radiation beam that passes through the analysis region, and a log ratio circuit that utilizes integrated electrical signals corresponding to the two source energization intensity levels to provide background corrected concentration information on the element of interest i

Abstract: A durable, low cost, disposable, single test reagent package with plural compartments that maintain reagents separate during long term storage and permits combining of compartment contents without opening the vessel in a simple, rapid, and controlled manner includes a body component and an imperforate cooperating cover component. The body component defines a central compartment and an annular compartment surrounding the central compartment. Each compartment is upwardly open with annular ridge structure between the two compartments, and reagent material is stored in at least one of the compartments.

Abstract: In a method for colorimetric determination of calcium, the sample to be analyzed is mixed with a dye reagent of pH value at which that reagent does not produce a predetermined change when complexed with calcium ions; a first colorimetric measurement is made on the mixture of the sample and dye reagent; a second reagent is added to the mixture of the sample and dye reagent to shift the pH and activate the dye reagent producing the predetermined change; and then a second colorimetric measurement is made on the resulting mixture, the difference between the two colorimetric measurements being a measure of calcium in the sample.

Abstract: An aqueous reagent for determining inorganic phosphate in a protein-containing liquid biological sample comprises a molybdate salt, an acid capable of reacting with the molybdate salt to form molybdic acid for complexation with phosphate to form phosphomolybdate complexes, a ferric salt in an amount sufficient to inhibit turbidity in the sample, and a nonionic surfactant reagent in an amount sufficient to further inhibit turbidity in the sample, the molybdate salt and the acid being present in amounts sufficient to form an amount of molybdic acid sufficient to produce a detectible color change when complexed with phosphate in the sample.

Abstract: A chemical analysis system for analyzing a plurality of independent specimens that have time varying characteristics includes a circumferential array of analysis regions that hold the specimens. The analytical regions are sequentially and repetitively sensed and resulting analysis signals corresponding to monitored specimen characteristics are stored in corresponding memory locations. A signal transmission channel connected between the sensor and the memory includes a signal storage capacitor and variable slew rate circuitry.

Abstract: An analysis system for measuring a plurality of parameters of a fluid sample comprises a housing, and a flow-through cell in the housing that has opposed surfaces with at least two ports in each surface. One of the ports is an inlet port, a second of the ports is an outlet port, and at least two of the ports are sensing ports. A sample flow path including a serpentine portion in the cell serially connects the ports and extends from a port in one surface to a port in the other surface and back to a port in the one surface, and a sensor is disposed in sealing engagement with each sensing port and forms a portion of the serpentine flow path so that sample fluid to be analyzed contacts a surface of each sensor.

Abstract: A reference liquid system for use with a chemical analyzer that has a plurality of ion selective electrodes comprises a plurality of reference liquids, each of which has a first salt component such that ions of a first element to be measured are present in a predetermined concentration, a second salt component such that ions of a second element to be measured are present in a predetermined concentration, and an error compensation salt component present in a concentration effective to adjust(a) the activity coefficient factor and/or(b) the junction potential factorto reduce the error involved in use of the compensated reference liquid to less than fifty percent of the error involved in use of a corresponding uncompensated reference liquid.

Abstract: A storage and manipulating tool for replacement plunger heads includes a set of storage cavities in which replacement plunger heads (syringe tips) are stored. Each plunger head has an annular flange, and a socket for receiving the end of a cooperating plunger shaft and is stored in its cavity with its socket facing the open end of the storage cavity. The tool also includes elongated passage defining structure for receiving a related plunger shaft. The cross-sectional dimension of the elongated passage is uniform along its length and is less than the annular flange portion of a replacement plunger head stored in a cavity such that axial movement of a plunger shaft in the elongated passage is effective to remove the attached plunger head. The exposed attachment end of the plunger shaft is then inserted into a storage cavity to attach a replacement plunger head for removal from the storage cavity without handling the sealing surfaces of the plunger head.

Abstract: A clinical analyzer system flows a small volume (less than 200 microliters) of liquid sample to be analyzed from an inlet port past a sensor array to a series of analysis chambers. The sensor array includes two optical sensor units that are spaced a fixed distance apart, and each sensor unit transmits a beam of infrared radiation through the flow tube for sensing by a detector. Each detector output has a low value when blood is in the flow tube, an intermediate value when air is in the flow tube, and a high value when a clear liquid is in the flow tube. Control logic senses changes in the outputs of the detectors and accurately indicates gas-liquid interface transitions. The noninvasive system accurately locates leading and trailing edges of samples of biological fluids to be analyzed, monitors the integrity of those samples, and distinguishes between types of sample liquids processed by the analyzer.

Abstract: An improved analytical cuvette assembly includes structure defining a first chamber region that has a loading port through which a first reaction component is introduced for storage, structure defining a second chamber region having a loading port through which a second reaction component is introduced for storage, and barrier structure between the first and second chamber regions that has a crest portion that defines the lower edge of a transfer passage between the two chamber regions. The second chamber region includes an analysis region where the reaction product resulting from mixture of the two reaction components is subjected to analysis.

Abstract: A blood gas control liquid comprises a stable oil-in-water emulsion that has an oxygen solubility coefficient of at least 10 ml O.sub.2 per 100 ml emulsion and a viscosity of less than 10 centipoises. The emulsion includes water, 5-40 percent by volume of a water-insoluble non-protein compound material, 0.25-10 percent by volume of a nonionic surfactant, a pH buffering agent and a preservative agent which is substantially non-reactive with the pH buffering agent. A preferred blood gas control liquid has a density of about 1.08. The blood gas control liquid has a pH in the range of 7-8, a partial pressure of carbon dioxide in the range of 15-80 millimeters Hg, and a partial pressure of oxygen in the range of 20-600 mm Hg.

Abstract: A spectroanalytical instrument includes burner structure and a nebulizer for furnishing sample in fog form for flow through a premix chamber to the burner structure. Flow structure extending from a chamber port to a drain port provides a condensate flow path from the chamber to a drain. Trap structure is disposed in series in the flow path between the chamber port and the drain port, and drain line closure apparatus is switched between a first condition in which the drain line is closed and a second condition in which the drain line is opened by a control responsive to liquid in the trap structure such that the drain line is initially closed and is opened automatically in response to accumulation of condensate liquid in the trap structure to enable maintenance of positive pressure in the premix chamber.

Abstract: A one-piece disposable electrode comprising a sealed chamber containing an electrolyte solution, silver-silver chloride conductor in the electrolyte solution in the chamber and a cast-in-place membrane essentially flush with an exterior wall of this chamber for exposure to a biological fluid whose ion content is to be measured.

Abstract: Method and apparatus for automatically depositing predetermined reproducible amounts of nebulized samples into a furnace atomizer of an atomic absorption spectrophotometer, the atomizer being provided with an aperture, wherein a plurality of sample containers containing samples to be analyzed are arranged and successively transported on a sample supporting device, with the sample containers being open at their upper ends. The samples are aspirated from the containers via a suitable means and into a nebulizer-mixing chamber device wherein they are nebulized and mixed until such time that the nebulized sample achieves full equilibrium therein. A means is provided for depositing the nebulized and now equilibrated sample from the chamber device through the aperture into the furnace atomizer.

Abstract: An analysis system for measuring a plurality of parameters of a fluid sample comprises a housing, and a flow-through cell in the housing that has opposed surfaces with at least two ports in each surface. One of the ports is an inlet port, a second of the ports is an outlet port, and at least two of the ports are sensing ports. A sample flow path including a serpentine portion in the cell serially connects the ports and extends from a port in one surface to a port in the other surface and back to a port in the one surface, and a sensor is disposed in sealing engagement with each sensing port and forms a portion of the serpentine flow path so that sample fluid to be analyzed contacts a surface of each sensor.