| 摘要 |
An electrochemical measuring cell 1 for detecting several components of a gas mixture, has a plurality of working electrodes 8, 12, 13, a common counter electrode 21 and a common reference electrode 20 in an aqueous electrolyte 3. A diffusion membrane 7, 11 covers the working electrodes 8, 12, 13 and individual shutters 9, 14 restricting the entry of gas to the individual working electrodes 8, 12. The selectivity of the detection of different gas components is improved by a barrier 19, comprising a gap full of electrolyte between the two parts of the diffusion membrane, preventing cross diffusion within the diffusion membrane 7, 11 between at least two of the working electrodes 8, 12. As described, the potentials of the working electrodes are set such that oxygen is reduced at the first working electrode 8, carbon monoxide is fully oxidised and hydrogen partially oxidised at the second working electrode 12, and excess hydrogen diffuses through the diffusion membrane 11 to the third working electrode 13 where it is completely oxidised. |
