Gas sensing element employable in an exhaust system of an internal combustion engine

A gas sensing element comprising:

• first and second chambers into which an objective gas to be measured is introduced;
• a first diffusion resistive passage connecting said first chamber to an outside of said gas sensing element;
• a second diffusion resistive passage connecting said first chamber to said second chamber;
• a pump cell provided on a surface defining said first chamber for pumping oxygen in accordance with an applied voltage;
• a monitor cell provided on either a surface defining said first chamber or a surface defining said second chamber;
• and
• a sensor cell provided on a surface defining said second chamber and responsive to application of a predetermined voltage for generating a sensor current representing a specific gas concentration in said objective gas,
• wherein
• said voltage applied to said pump cell is controlled based on a limiting current obtained when a voltage is applied to said monitor cell.

A gas sensing element comprising:

• first and second chambers into which an objective gas to be measured is introduced;
• a first diffusion resistive passage connecting said first chamber to an outside of said gas sensing element;
• a second diffusion resistive passage connecting said first chamber to said second chamber;
• a first pump cell provided on a surface defining said first chamber for pumping oxygen in accordance with an applied voltage;
• a second pump cell provided on a surface defining said second chamber for pumping oxygen in accordance with an applied voltage;
• a sensor cell provided on a surface defining said second chamber and responsive to application of a predetermined voltage for generating a sensor current representing a specific gas concentration in said objective gas,
• wherein
• a pump current is produced from at least one of said first and second pump cells in accordance with the pumping of oxygen, and
• said pump current is utilized to control the voltage applied to said one of said first and second pump cells.

A gas sensing element comprising:

• first and second chambers into which an objective gas to be measured is introduced;
• a first diffusion resistive passage connecting said first chamber to an outside of said gas sensing element;
• a second diffusion resistive passage connecting said first chamber to said second chamber;
• a monitor cell provided on at least one of a surface defining said first chamber or a surface defining said second chamber;
• a first pump cell provided on a surface defining said first chamber for pumping oxygen in accordance with an applied voltage;
• a second pump cell provided on a surface defining said second chamber for pumping oxygen in accordance with an applied voltage;
• and
• a sensor cell provided on a surface defining said second chamber and responsive to application of a predetermined voltage for generating a sensor current representing a specific gas concentration in said objective gas,
• wherein
• said voltage applied to at least one of said first and second pump cells is controlled based on a limiting current obtained when a voltage is applied to said monitor cell.