Patent 4272330 Issued on June 9, 1981. Estimated Expiration Date: March 3, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
205/785, With heating or temperature sensing204/406, With significant electrical circuitry or nominal computer device204/412, Three or more electrodes204/425, With impressed current means204/426, Planar electrode surface205/784Gaseous oxygen or oxygen containing compound
This specification discloses a device to determine the partial pressure of oxygen in a gaseous atmosphere. The device, which is immersed in the atmosphere, is constructed to define an enclosed volume in which the atmosphere can be established by means of a small leak. The enclosing structure contains two partitions, a pump cell and a sensor cell, which can conduct oxygen ions and act as electrochemical cells. When attached to an external power supply, the current IP drawn through the pump cell either adds or removes (from or to the ambient) gaseous oxygen from the volume. As a result of the pumping action, an EMF (VS) develops across the sensor cell which can be used to measure the change in oxygen partial pressure in the volume relative to the ambient. In a transient mode, a voltage step is applied to the pump cell removing (adding) oxygen from (to) the volume. The rate of change of VS with respect to time at the instant of the voltage step is measured. This time derivative is inversely proportional to oxygen partial pressure.
March 3, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
