摘要 |
A sensor for detecting the amount of O2 and combustible gas in a gaseous mixture uses two electrochemical cells (20,40) operating in sequence, to detect oxygen and gaseous combustible contents respectively; the first electrochemical cell (20) is a molten carbonate electrochemical cell operating at a temperature between 400 and 700 DEG C and is used to remove O2 in combination with CO2 from the oxygen/combustibles gas mixture to provide a low temperature measurement of the oxygen content of the gas mixture. The second electrochemical cell (40) is an oxygen ion conductive using catalyzing electrodes (44, 46) and an external source of O2, e.g. air, to cause combustion of the combustible components of the mixture. The cells (20, 40) each have electrodes (24,26;44,46) applied across cell-walls to apply a potential to cause oxygen transport across the cell walls. The current flowing through across the cell-walls in a measure of either the oxygen content or the oxygen required to oxidize the combustible gaseous contents. |