| 摘要 |
Electrochemical measurement cells having a solid electrolyte which conducts oxygen ions, e.g. zirconium dioxide, are used in many different fields for the measurement of the oxygen partial pressure in measurement gases. If the measurement gas also contains combustible gases in addition to oxygen, these are catalytically oxidised at the platinum electrodes of the measurement cell. The object of the invention is to provide a method by which the proportion of oxygen and of oxidisable gases can be simultaneously determined using a diffusion-current-limited measurement cell. The method is based on the idea that oxidisable gases on combustion reduce the oxygen content of the measurement gas. The pumping current Ip is set to produce a minimum or maximum oxygen partial pressure at an electrode pair (2a, 2b) of the measurement cell with simultaneous measurement of the potential difference EMK (EMF) at another electrode pair (9a, 9b). From the measured values of the EMF and the pumping current (Ip), the content of oxygen and oxidisable gases in a measurement gas is determined by comparison with measurement curves of a known gas composition (Fig. 1). <IMAGE>
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