Abstract: A block-shaped measuring chamber unit, especially for use in electrochemical measuring apparatuses for defining measuring chambers therein. The block-shaped unit has oppositely directed or otherwise differently orientated surface parts each defining a depression to be used as a measuring chamber. These depressions are interconnected by means of straight bores or passages extending through the block-shaped unit. The block-shaped unit is preferably made from machinable glass-ceramic.

Abstract: A reference liquid for the calibration and/or quality control of blood gas analyzers. The reference liquid comprises an aqueous phase and either polymer-coated microcapsules containing at least one organic substance functioning as oxygen carrier, or porous particles of a solid substance functioning as oxygen carrier. An example of the polymer-coated microcapsules is nylon-coated microcapsules containing a mixture of perfluorotributyl amine and isooctane. An example of the porous particles of a solid substance is particles of porous silicone rubber.

Abstract: A package containing a reference liquid for the calibration and/or quality control of blood gas analyzers. The reference liquid is enclosed in a flexible, gas-tight container without any gas bubbles in the container, and to avoid any danger of formation of gas bubbles, the total gas pressure in the liquid is kept below 600 mm Hg at 37.degree. C. The container is preferably a laminate bag of aluminum foil with interior layer of heat sealable plastic of low gas permeability, preferably a polyacrylonitrile copolymer.

Abstract: The invention relates to a membrane mounting device for mounting a membrane or foil in a stretched condition at one end of a rod-shaped or tubular member, such as a measuring electrode member. The mounting device comprises a membrane to be mounted as well as a resilient mounting ring for retaining the membrane in its mounted condition. The resilient mounting ring is preferably kept in a condition substantially free from tension. However, immediately before use of the mounting device the ring may be tensed or stretched, and one end of a rod-shaped or tubular member may then be inserted in the membrane mounting device whereby the membrane may automatically be mounted at the said end of the rod-shaped or tubular member.

Abstract: A process for automatic titration wherein the dosage of titrant is controlled by a digital computer, the titration being started with at least one dosage of a preselected size, each dosage of titrant thereafter and throughout the total course of the titration being precalculated and controlled on the basis of transducer signal change per added titrant volume unit at the preceding dosages in such a way that the titrant dosages are relatively smallest around the equivalence point.

Abstract: An electrode for polarographic measurement of the partial pressure of oxygen in gases or solutions, comprising a cathode in contact with and outwardly shielded by a gas permeable membrane, a silver/silver bromide half cell serving as anode, and a bromide-containing aqueous electrolyte in contact with the anode and the cathode, the bromide ion concentration of the electrolyte being between 10.sup.-4 and 5 .times. 10.sup.-3 M, preferably 5 - 6 .times. 10.sup.-4 M.

Abstract: Electrochemical measuring electrodes often have a thin foil-shaped membrane, e.g. made of a plastic foil, which is arranged at one end of a cylindrical portion of the electrode and maintained in position by means of a resilient ring-shaped member, e.g. an O-ring, which presses the folded-over edge portion of the membrane against the outside of the cylindrical portion. It is now suggested to guide the ring-shaped holding member in such a way on the cylindrical portion that it protrudes beyond the membrane and thereof. The guiding may be provided by means of a circumferential groove in the cylindrical portion near the membrane end thereof.

Abstract: The invention relates to a method and apparatus for measuring one or more data of blood samples, such as oxygen saturation, contents of hemoglobin, bicarbonate, sodium, potassium, etc. involving hemolyzation of the blood sample. The blood sample is passed into a conduit and hemolyzed therein by imparting ultra-sonic waves to all parts defining said conduits. Measurement is performed after and possibly also prior to hemolyzation. In its preferred embodiment the apparatus according to the invention comprises a computer for automatically controlling the operational sequence of the components of the apparatus and for receiving measuring signals from measuring devices of the apparatus and converting said signals into immediately understandable digital data.

Abstract: The invention relates to a method for collecting a blood sample from a blood vessel, such as an artery, by means of a syringe, preferably of the type having a piston displaceably mounted within a cylinder which is provided with a hollow needle. Before the needle is inserted in the blood vessel from which the blood sample is to be collected the piston is displaced to a retracted position, and the cylinder space defined by the piston is vented to the atmosphere. The invention also relates to a blood sampling syringe having means for venting the cylinder space to the atmosphere in a retracted position of the syringe piston.

Abstract: Calcium di(aryl)phosphates, the aryl groups each carrying at least one carbon chain containing at least 3 carbon atoms, are used as electroactive materials in calcium electrodes. In a preferred calcium electrode, the calcium di(aryl)phosphate is calcium di(p-n-octylphenyl)phosphate which is incorporated in a membrane of polyvinyl chloride plasticized with di(p-n-octyl)-phenylphosphonate.