| 摘要 |
PURPOSE:To calibrate an oxygen concn. cell without using standard gas, by allowing a pump current to flow to the oxygen pump part of an oxygen sensor element and bringing the atmosphere above the gas electrode to be measured of the oxygen concn. cell of the oxygen sensor element to one having the same oxygen concn. as a calibration gas to perform calibration. CONSTITUTION:The measuring chamber 18 of an oxygen sensor element 10 set to predetermined temp. by a heater part 40 is filled with a calibration gas containing oxygen at every concn. and the reference generated power E0 of an oxygen concn. cell part B corresponding to the concn. O2 of oxygen in the calibration gas is calculated. Further, the chamber 18 is brought to the atmosphere of the open air to calculate a reference oxygen pump current IPC wherein the generated electromotive force of the cell part B corresponds to the power E0 by supplying a current to pump electrodes 12, 13. When the element 10 is calibrated, the current IPC is allowed to flow to an oxygen pump part P in such a state that the atmosphere is allowed to flow to the element 10 to bring the atmosphere of the chamber 18 to a prescribed oxygen concn. and the generated electromotive force of the cell part B generated corresponding thereto is calibrated to the voltage E0 through a buffer amplifier. |
