Apparatus for simultaneous measurement of gas concentrations in breathed and expired air

摘要

The apparatus includes a galvanic CO2-sensing cell with a carbonate-free Na<+>-ion-conducting solid electrolyte (1) and two mixed-solid electrodes (2,3) both containing powdered precious metal and finely divided oxygen-ion-conducting solid electrolyte. Na2CO3 and oxide are combined into a compound with release of CO2. The O2-sensing cell has one electrode (7) with an oxygen-ion-conducting solid electrolyte (9) and an air reference electrode (8). Both cells occupy a substantially isothermal region of a heater (17) and their four electrodes in common with a temperature sensor (10) are connected to an electronic signal processor.