Determining selected time points during regular changes of oxygen@ concn. contained in liquid flowing in vessel - using galvanic cell, with two electrodes with partition in-between, on oxide ion conducting solid body without or with heating

摘要

The successive vol. parts of the medium flowing in the vessel (9), are firstly conducted over one electrode and then over the other electrode, and the electrical voltage occurring between the two electrodes (1, 2) is measured as a prim. signal and evaluated. In the event of multiple fluctuations of this signal at times, which are small compared to the time for a regulating cycle, with the integration of the voltage over a time, which is smaller than that for the regulating cycle, a sec. signal value is formed. After considering the thoroughness of the mixture and the reaction condition of the flowing medium at the place of the galvanic cell, with the reaching of a threshold or a max. value of the prim. signal or a threshold or a max. value of the sec. signal, the time point for activating a regulating operation is selected. USE/ADVANTAGE - Oxygen sensing system for regulating air-fuel mixture in motor vehicles. Unit miniaturised and quickly heats up in hot exhaust gas. Gives refinement and reduced cost of regulating of noxious emission redn.