Abstract: In order to calibrate a measurement apparatus used for determining at least the pH and pCO.sub.2 values in aqueous media, two aqueous base solutions A and B with good storage stability are mixed at a defined ratio immediately prior to calibration, the desired pH and pCO.sub.2 values being provided for calibration of the measuring electrodes of the measurement apparatus only after chemical reaction of the base solutions A and B has taken place.

Abstract: In order to simplify the performance of serial measurements by means of a measuring device for determining chemical parameters of an aqueous sample, with at least one symmetrical, ion-sensitive membrane being located between the sample and an electrolytic medium and the sample and the electrolytic medium being in contact with reference electrodes connected to an evaluation unit, a measuring element is provided which can be inserted into a measuring device and which has a sample chamber connected with a reference chamber via a bore. At least one measuring chamber is provided, which is separated from the sample chamber by a symmetrical, ion-sensitive membrane. The reference chamber and all measuring chambers contain electrolytic media into which are dipped the reference electrodes located in the measuring device.

Abstract: An analyzing apparatus for the purpose of analyzing samples of body fluids, comprising a sample feeding device and a measuring channel in which measuring probes are contained. In order to attain good reproducibility and uniform conditions of treatment of the samples the measuring channel is separated by means of a valve from a storage tank communicating with the sample feeding device.

Abstract: Due to the size of the devices used for the excitation and measuring of light, conventional sensor elements for optically determining the concentrations of substances contained in gaseous and liquid samples, featuring an indicator layer with one or more indicator substances, are not well suited for use with microanalysis equipment, nor are they easy to mass-produce. These disadvantages are eliminated by integrating on the carrier layer (1) at least one photosensitive element (3) and its electric contact leads in planar arrangement, and by establishing optical contact between the indicator substance (7, 7') of the indicator layer (6) stimulated by the excitation radiation (11), and the photosensitive elements (3).

Abstract: In order to produce a small-volume flow measuring cell with good flow characteristics in a sensor device for determining the concentration of a substrate in a sample medium, comprising an enzyme electrode which is covered by a membrane and a reference electrode, both of which are in contact with the measuring cell, the proposal is put forward that the reference electrode be located outside of the membrane cover of the enzyme electrode and that the maximum extension of the flow measuring cell normal to the flow direction of the sample medium essentially be the same as the diameter of the sensitive layer of the enzyme electrode.

Abstract: In order to reduce the measuring volume in a device for measuring chemical and physical parameters of liquid or gaseous media by means of optical sensor elements whose optodes may be replaced easily, a measuring unit with a sample channel is provided which may be inserted into a supporting frame of the device and which may be connected to ingoing and outgoing sample lines via capillary bores. The measuring unit contains a sensor carrier forming the boundary of the sample channel on one side, which sensor carrier has bores holding the optodes. The indicator film of each individual optode is situated in the plane of the sensor carrier facing the sample channel.

Abstract: Electromagnetically actuated valve, comprising an actuating device, a movable plunger and a valve chamber with an opening for the medium passing through it, which opening may be closed by the plunger. In order to ensure safe functioning of the valve at small closing forces, the valve chamber is totally sealed against the actuating device and the movable plunger by means of a flexible diaphragm, the diaphragm being fitted into the housing along its circumference and being pressed against the edge of the opening by the movable plunger.