Abstract: In a method of optically determining the total hemoglobin concentration (tHb) in non-hemolyzed whole blood, using at least two wavelengths for measuring, a first wavelength of .lambda.<805 nm and a second wavelength of .lambda.>805 nm is employed, such the following is valid for the absorption coefficients of hemoglobin derivatives O.sub.2 Hb and RHb at the two measurement wavelengths .lambda..sub.1 and .lambda..sub.2 : .sigma.O(.lambda..sub.1).about..sigma.R(.lambda..sub.2) and .sigma.R(.lambda..sub.1).about..sigma.O(.lambda..sub.2). The sum of absorption values A.sub.1 and A.sub.2 measured at wavelengths .lambda..sub.1 and .lambda..sub.2 will be a quantity which is proportional to the total hemoglobin concentration tHb and independent of the oxygen saturation O.sub.2sat.

Abstract: An optical indicator for determining the activity of an ion in a sample is provided with an ionophor which is capable of selectively binding the ion to be measured. The ionophor has at least two functional groups that can form an electron donor acceptor (EDA) complex, the complex bond being broken up by the attachment of the ion to be determined. This will lead to a change in at least one of the measurable optical properties of the indicator in dependence on the activity of the ion to be measured.

Abstract: A planar sensor for determining a chemical parameter of a sample, includes a substrate whose surface is at least partly plane and is provided with at least one potentiometric or amperometric and, possibly, an optical transducer, and one or more biochemical components. The transducer and the biochemical component are provided on the surface of the substrate, or at least part of the surface, as a sensor spot, and a cover membrane surrounding this sensor spot, is heat welded to the surface of the substrate. Those sensor spots that include a potentiometric or amperometric transducer are in contact with a strip conductor attached to the plane surface of the substrate and the thermal seal of the cover membrane is interrupted where the conducting strips lead away from the sensor spots.

Abstract: A reagent bottle suitable for insertion into a sample analyzer features a sample discharge opening plugged by an elastic, pierceable stopper, and an air inlet. Both the sample discharge opening and the air inlet are located on the same side of the reagent bottle, the axes of the two openings running parallel to each other, such that both openings can be docked onto corresponding sampling and air inlet elements of the analyzer in one and the same working process when the reagent bottle is inserted into the analyzer. The elastic stopper is covered on its outside by a protective foil and has a recess at a puncturing site enabling the sampling element to puncture the foil more easily. Bordering on the recess of the stopper is an area which is prepunctured but offers a tight elastic seal.

Abstract: In a method for calibration of a pH measuring element whose ion-permeable, hydrophilic polymer layer is brought into contact with an aqueous solution prior to calibration, the aqueous solution is displaced or replaced by a gaseous calibrating medium, and residues of the aqueous solution remaining in the ion-permeable polymer layer. The gaseous calibrating medium contains a known amount of at least one component which is acid or basic in aqueous solution which reacts with the remaining residues of the aqueous solution in the polymer layer, such that a defined pH value is established in the polymer layer, which is employed for calibration of the measuring element.

Abstract: For the purpose of automatically drawing a liquid from a sealed glass ampoule the latter is held in a support in upright position with the ampoule bottom facing upwards, and the bottom is destroyed mechanically by inserting a withdrawing element. The liquid content of the ampoule is then sucked from a splinter-free zone of the glass ampoule.

Abstract: Electromagnetic actuating device, in particular for a valve, includes a plunger which is axially movable between two extreme positions, an electromagnetic coil surrounding the plunger actuating it, and a permanent magnet holding the plunger in one of its extreme positions, and at least one pole plate located between plunger and permanent magnet. The holding force of the permanent magnet is considerably increased by providing that the permanent magnet, which is configured as a flat disk, be completely covered by the pole plate on the side facing the plunger.

Abstract: An optochemical sensor for measuring concentrations of analytes is provided with a reactive matrix preferably made of polymeric material capable of swelling. Further provided are a mirror layer and a layer of a plurality of discrete islands that are electrically conductive, between which layers the reactive matrix is positioned, the diameter of the islands being smaller than the wavelength of the light employed for monitoring and evaluation.

Abstract: A sensor with a first, second and third force pick-up includes a piece of foil made of piezoelectric material which serves all three pick-ups and carries a number of electrodes. The second and third pick-up are located one on either side of the first pick-up and are characterized by a smaller pick-up surface than the first one. For measuring blood pressure the sensor is pressed against a part of a patient's body such that the first force pick-up, i.e., the one in the middle, is at the shortest possible distance from a large artery. During measurement the absolute values of the changes in the measurement values of the three force pick-ups, which are due to the pulsating blood stream, are added. On the other hand the changes in the measurement values caused by interfering forces will cancel each other out.

Abstract: In a process for mixing two initial solutions to produce a working solution with an accurately defined mixing ratio, the two initial solutions are coarsely mixed in a first step, having a mixing ratio lying within a given range, and the value of an internal parameter of the working solution is determined in a second step. The values of this internal parameter are known and differ significantly for the two initial solutions. Then the accurate mixing ratio of the working solution is determined from the measured value of the internal parameter in a third step.

Abstract: A fluid-tight connection of capillary channels in components which are detachable from each other is established with the use of a sealing element. In order to compensate for slight deviations between the channel axes during the coupling of the components without creating any dead spaces, the sealing element is configured as a piece of flexible tubing adapting to the course of the capillary channels during component coupling, and a mounting element anchored in one of the components.

Abstract: A member has a solid carrier and a thin oxide layer which is arranged thereon and consists of iridium oxide and/or possibly at least one oxide of at least one other metal belonging to the fifth or sixth period and to one of the subgroups 5b, 6b, 7b and 8 of the Periodic Table of chemical elements and/or zirconium oxide. The oxide layer is monocrystalline and therefore very stable. The member can serve, for example, for the formation of at least one electrode which serves as a proton donor and/or proton acceptor and/or for the measurement and/or change of the pH value and/or for a coulometric measurement or for holding biologically active molecules and at the same time as an electrode and/or optical sensor.

Abstract: In a device for determining the concentration of a reagent from a group consisting of gases with acid or alkaline reaction in aqueous environments, and volatile acids and bases in liquid or gaseous samples, a sample chamber is situated in a housing and a unit for pH measurement with a reaction space is separated from the sample chamber by an ion-impermeable, gas-permeable membrane. The feeding of the reaction space with buffer solution is facilitated by connecting the reaction space by means of an ion-permeable channel to a reservoir for a buffer solution located outside of the pH measuring unit.

Abstract: A device for analyzing the metabolism of cells includes a supporting base which carries a pH measuring electrode, a control electrode designed for proton exchange with the liquid, a reference electrode, and a counterelectrode, and which, together with at least one other part, confines a hollow space containing the cells and a liquid. The electrodes are connected to electronic circuit elements. In the course of an analysis the pH value of the liquid is determined by means of the pH measuring electrode and the reference electrode. Between the control electrode and the counterelectrode an electric current is passed through the liquid and controlled such that the pH of the liquid is maintained at a constant preset value beneficial to the cells, by proton exchange with the control electrode. In addition, the amount of charge required for generating the current during the measuring period is determined to obtain a measure for the intensity of the metabolic process and thus for the vitality of the cells.

Abstract: In order to avoid dead volumes in a valve for control of a branch line departing from the main line in a valve chamber located in a valve housing, the valve chamber contains an elastomer part provided with a main channel and a branch channel departing from it, and the two ends of the main channel are sealingly connected with the main lines. The free end of the branch channel is sealingly connected with the branch line, and further that a valve lifter be provided in the valve housing, which acts on the branch channel in the branch-off area directly adjacent to the main channel of the elastomer part, thus reducing the cross-section of the branch channel, which is held in place by a counterpiece in the valve housing.

Abstract: A luminescence-optical indicator for determining the activity of alkali metals based on decay time includes at least three components that are chemically bound to one another, i.e., a fluorophor, a functional group with which the luminescence decay time of the fluorophor can be influenced, and a ionophor binding the alkali metal ions to be measured in a selective and reversible manner, the effect of the functional group on the decay time of the fluorophor being altered in dependence on the activity of the alkali metal ions.

Abstract: A feeder unit, which is used for selectively charging an analyzing apparatus with liquid or gaseous sample-, reference- or cleaning media, comprises a sample inlet and a feeder part hinged on the feeder unit at one end. The feeder part contains an intake passage for the cleaning medium to be entered, the sample inlet having a flexible feeder funnel cooperating with a washing element which is attached to the feeder part and can be introduced into the funnel. The feeder part is configured as a cover flap swinging around a fixed pin. The intake passage for the cleaning medium opens into the washing element and is also used for delivering liquid and gaseous reference media. The washing element is located on a support which is elastically attached to the cover flap, and fits into the flexible funnel when the cover flap is closed.

Abstract: An electrode arrangement includes at least one potentiometric measuring electrode located in a sample channel, a reference electrode located in a branch line, and a suction pump downstream of the diaphragmless entrance opening of the branch line into the sample channel the reference electrode being an ion-sensitive, i.e., preferably chloride-sensitive, membrane electrode.

Abstract: For quality control of packaged organic substances, preferably packaged foods and drugs, the materials to be examined are brought into contact with a planar optical sensor element which is applied on the inside of the wrapping and responds to a change in the gas composition in the gas space above the sample by a change in color or fluorescence. The change of one of the optical properties of the sensor element is detected visually or opto-electronically.

Abstract: Apparatus for withdrawing arterial blood has a protective tube having a mounting member on one end of the tube. The mounting member includes a conical seat for the receipt of a hollow needle. A connecting member is mounted on the other end of the tube. First and second capillaries, having respective ends, arc positioned within the tube. The first capillary is arranged concentrically within the second capillary so that an annular space is formed between the first and the second capillaries. The first capillary projects beyond both ends of the second capillary, and one end of each of the first and the second capillaries is mounted in the mounting member. The first capillary is connectable to a hollow-needle, and the other end of each of the first and the second capillaries is mounted in the connecting member which provides communication between the first and the second capillaries.