Gas concentration measuring apparatus compensating for error component of output signal

A gas concentration measuring apparatus comprising:

• a gas concentration sensor including a gas chamber, a first cell responsive to application of a voltage to pump oxygen molecules selectively out of and into gasses admitted into the gas chamber to produce an electric current indicative of a concentration of the oxygen molecules, a second cell working to determine a concentration of a specified oxygen containing gas component contained in the gasses having passed through the first cell, and a monitor cell working to monitor a concentration of residual oxygen molecules within the gas chamber and provide an output indicative thereof;
• an applying voltage correcting circuit working to determine a target voltage to be applied to said first cell by looking up a predetermined voltage-to-current relation as a function of the electric current produced by said first cell, said applying voltage correcting circuit correcting one of the target voltage and the predetermined voltage-to-current relation as a function of the output of said monitor cell;
• and
• an applying voltage controlling circuit working to control voltage applied to said first cell into agreement with the target voltage determined by said applying voltage correcting circuit.

A gas concentration measuring apparatus comprising:

• a gas concentration sensor including a gas chamber, a first cell responsive to an application of voltage to pump oxygen molecules selectively out of and into gasses admitted into the gas chamber to produce an electric current indicative of a concentration of the oxygen molecules, a second cell working to produce an electric current for determining a concentration of a specified oxygen containing gas component contained in the gasses having passed through the first cell, and a monitor cell working to monitor a concentration of residual oxygen molecules within the gas chamber and provide an output indicative thereof;
• an applying voltage determining circuit looking up a predetermined voltage-to-current relation to determine a target voltage to be applied to said first cell as a function of the electric current produced by said first cell so as to preclude said first cell from decomposing the specified oxygen containing gas component;
• and
• a second cell output correcting circuit working to correct the electric current outputted by said second cell as a function of the output of said monitor cell.

A gas concentration measuring apparatus comprising:

• a gas concentration sensor including a gas chamber, a first cell responsive to application of a voltage to pump oxygen molecules selectively out of and into gasses admitted into the gas chamber to produce an electric current indicative of a concentration of the oxygen molecules, a second cell working to output an electric current for determining a concentration of a specified oxygen containing gas component contained in the gasses having passed through the first cell, and a monitor cell working to monitor a concentration of residual oxygen molecules within the gas chamber and provide an output indicative thereof;
• an applying voltage determining circuit working to determine a target voltage to be applied to said first cell by looking up a predetermined voltage-to-current relation as a function of the electric current produced by said first cell;
• a first correcting circuit working to correct on of the target voltage and the predetermined voltage-to-current relation as a function of the output of said monitor cell so as to preclude said first cell from decomposing the specified oxygen containing gas component;
• an applying voltage controlling circuit working to control voltage applied to said first cell into agreement with the target voltage provided by said applying voltage correcting circuit;
• and
• a second correcting circuit working to correct the electric current produced by said second cell as a function of the output of said monitor cell to determine the concentration of the specified oxygen containing gas component.

A gas concentration measuring apparatus comprising:

• a gas concentration sensor including a gas chamber, a first cell responsive to an application of a voltage to pump oxygen molecules selectively out of and into gasses admitted into the gas chamber to produce an electric current indicative of a concentration of the oxygen molecules, a second cell working to determine a concentration of a specified oxygen containing gas component contained in the gasses having passed through the first cell, and a monitor cell working to monitor a concentration of residual oxygen molecules within the gas chamber and provide an output indicative thereof, said first cell being formed in a solid electrolyte element;
• a resistance determining circuit working to determine a resistance to the solid electrolyte element;
• an applying voltage determining circuit working to determine a target voltage to be applied to said first cell by looking up a predetermined voltage-to-current relation as a function of the electric current produced by said first cell;
• an applying voltage correcting circuit correcting one of the target voltage and the predetermined voltage-to-current relation as a function of the resistance determined by said resistance determining circuit;
• and
• an applying voltage controlling circuit working to control voltage applied to said first cell into agreement with the target voltage provided by said applying voltage correcting circuit.