Abstract: A process and an arrangement for determining the perfusion factor of a gas in a sample, particularly of oxygen dissolved in blood flowing through biological tissue, includes measuring the amount of gas diffused from the sample by means of a polarographic cell which comprises a reference electrode having a heat conductive surface which is adapted to be placed in heat-transmitting relationship over a portion of the sample, and a sensor electrode in electrolytic contact with the reference electrode so as to generate a signal indicative of the amount of gas being diffused from the sample portion. A heating unit comprising a high frequency generator to establish a high frequency field in the sample is also provided for heating the sample diathermically to a desired temperature.

Abstract: A platinum oxygen-pressure measuring electrode is connected with a reference electrode. An indicating device for indicating the oxygen pressure is connected with both of the electrodes, and an arrangement is interposed between the electrodes and an object to be measured and has a surface which is to be placed against the object. The arrangement offers to the diffusion of oxygen from the surface to the measuring electrode a resistance which is greater than the resistance which is offered to such diffusion of the oxygen through the object to be measured.