Sensor and method for accurately measuring concentrations of oxide compounds in gas mixtures

A sensor for accurately measuring a concentration of an oxide compound in a gas mixture, comprising:

• a chamber adapted to receive the gas mixture;
• a first cell means comprising a first internal electrode inside said chamber, a first external electrode outside said chamber, and a first electrolyte body therebetween, said first electrolyte body is substantially permeable to oxygen ions when said first electrolyte body is electrically biased during operation of the sensor, said first internal electrode comprising a perovskite having selectivity to reduce the oxygen and, not the oxide compound;
• and
• a second cell means comprising a second internal electrode inside said chamber, a second external electrode outside said chamber, and a second electrolyte body therebetween, said second electrolyte body is permeable to said oxygen ions when said second electrolyte body is electrically biased during operation of the sensor, said second internal electrode comprising a material having selectivity to concurrently reduce both the oxygen and the oxide compound;
• whereby first and second electrical characteristics associated with said first and second cell means are measured and the concentration of the oxide compound in the gas mixture is determined by mathematically combining said first and second electrical characteristics.

A method for accurately measuring a concentration of an oxide compound in a gas mixture, comprising the steps of:

• exposing the gas mixture to a first internal electrode comprising a perovskite and a second internal electrode comprising a metal oxide;
• selectively reducing the oxygen with said first internal electrode without substantially depleting the oxide compound in the gas mixture;
• reducing the oxide compound with said second internal electrode after said first internal electrode depletes the oxygen;
• and
• measuring electrical characteristic associated with said second internal electrode to determine the concentration of the oxide compound in the gas mixture.

A method for accurately measuring a concentration of an oxide compound in a gas mixture, comprising the steps of:

• exposing the gas mixture to first internal and second internal electrodes, said first electrode comprising a perovskite;
• selectively reducing the oxygen with said first internal electrode without substantially depleting the oxide compound in the gas mixture;
• reducing both the oxygen and the oxide compound with said second internal electrode;
• measuring first and second electrical characteristics associated with said first internal and second internal electrodes respectively;
• and
• determining the concentration of the oxide compound in the gas mixture by mathematically combining said first and second electrical characteristics.