Abstract: A combined sensor for sensing partial O.sub.2 pressure and partial CO.sub.2 pressure and comprising measuring electrodes, a reference electrode, a diaphragm covering the electrodes and an electrolyte layer between the electrodes and the diaphragm wherein the reference electrode has disposed around it a screening of gold which is at the same potential as the reference electrode and the electrolyte contains a defined concentration of a soluble silver compound or of a silver complex.

Abstract: Calibration of sensors of the type used for the cutaneous determination of blood oxygen and carbon dioxide levels is facilitated by providing separate sensor units, alternatively and removably connectable to a calibration device and to the measuring devices with which they are used for such determinations. The sensor units contain, in addition to a sensor electrode, a data memory in which is stored calibration data generated when the sensor unit is connected to the calibration device. The calibration device can provide a plurality of calibration stations, each capable of supplying a standard gas to a connected sensor and, in response to signals from the sensor exposed to the standard gas, generating data signals representing the calibration of the sensor, which signals are transmitted to the data memory of the sensor unit. Upon connection of the sensor unit to the measuring device, the calibration data from the data memory of the sensor unit are used as a calibration base for measurements by the sensor.

Abstract: An apparatus for the simultaneous determination of the cutaneous blood gas concentration and of the blood gas availability for the correction of physiologically caused errors of the measured value of the cutaneous blood gas concentration by means of two heated blood gas electrodes in structural unity, of which one is distinguished by maximum gas consumption.

Abstract: The concentration of substrates of enzyme reactions is measured by determining the current produced at an platinum or gold electrode by oxidizing an acceptor utilizing a measuring device comprising a measuring cell, an enzyme electrode in contact with the fluid sample and containing an platinum or gold electrode, an enzyme layer and a reference electrode in contact with the fluid sample. In this manner important physiological parameters, such as the concentration of lactate and glucose in fluid biological samples, can be measured quickly and accurately.

Abstract: The concentration of substrates of enzyme reactions is measured by determining the current produced at a platinum or gold electrode by oxidizing an acceptor utilizing a measuring device comprising a measuring cell, an enzyme electrode in contact with the fluid sample and containing a platinum or gold electrode, an enzyme layer and a reference electrode in contact with the fluid sample. In this manner important physiological parameters, such as the concentration of lactate and glucose in biological fluids, can be measured quickly and accurately.

Abstract: An electrode arrangement for application to a body surface for bloodless measurement in connection with the concentration or the partial pressure of a gas in the blood comprising a sensor unit having a face member for body contact, and a heating unit coupled to the sensor unit for transmitting to said face member a thermal condition for thermal stimulation of the local blood circulation. In a further embodiment, the sensor unit includes at the face member a cover membrane permeable for a gas to be measured.