Patent ID: 7862703

Claim:
A method for pumping a sealed internal reference chamber of a solid electrolyte oxygen sensor, having an internal electrode and an external electrode, during a dynamically controlled, null balancing, calibration process, said method comprising: a. initializing a set of pumping current pulse parameters controlling pulse ON time, post pulse RELAXATION time and pulse magnitude; b. applying a pulsed pumping current based on said set of pulse parameters to the internal and external electrodes, wherein the application of current transitions the chamber from a substantially evacuated state to a substantially null or balanced oxygen partial pressure state with respect to an applied external calibration gaseous environment; c. periodically comparing the Nernst voltage of the sensor to a predetermined limit to determine whether the chamber is at a null or balanced state; d. comparing an elapsed time from the application of said pulsed pumping current to a third predetermined time limit to determine if the sensor has failed, and e. progressively reducing at least one of the magnitude, ON time and RELAXATION time of said pumping current pulses to slow the transition as the chamber approaches the null or balanced oxygen partial pressure state.