| 摘要 |
An electrochemical electrode device for simultaneously measuring the partial pressures of two gasses in a medium of limited gas availability one of which is measured potentiometrically and another one of which is measured polarographically comprises an electrode body (18) constituting a reference electrode relative to a pH-electrode (19) of a potentiometric electrode system, and a anode relative to a cathode (20) of a polarographic electrode system. Furthermore, the electrode device comprises an electrolyte solution (28) enclosed between the electrode body and a membrane (30). The membrane comprises a basic membrane layer (31), preferably of polytetrafluoroethylene (PTFE) or fluoroethylenepropylene (FEP) of a thickness of about 12 mu m, and a covering (32), preferably a polypropylene layer of a thickness of about 15 mu m, which covers part of the basic membrane layer so that an uncovered area (34) is constituted in front of the pH-electrode. The uncovered area constitutes a first membrane part showing high permeability to the first gas and constitutes together with the potentiometric electrode system and the electrolyte solution a first measuring system for measuring the partial pressure of the first gas. A covered area of the basic membrane layer constitutes together with its covering a second membrane part showing low permeability to the second gas and is arranged in front of the exposed measuring surface of the cathode so as to restrict the diffusion of the second gas to the cathode and together with the polarographic electrode system and the electrolyte solution to constitute a second measuring system for measuring the partial pressure of the second gas. |
