| 摘要 |
<p>Described are a sensing method and an oxygen sensor for detecting a change of oxygen partial pressure in an ambient atmosphere. The sensor (10) includes a sensing material (12) selected from metal or its oxides which, when at an elevated temperature and exposed to a gas containing a changing partial pressures of oxygen, is capable of changing from one metal or metal oxide phase to another such oxide phase and vice versa. A typical example is the CoO/Co3O4 system. Associated with such phase change is a change in a measurable physical property of the material. Heating means (19), connectable to a power source, able to maintain a temperature gradient across said sensing material are necessary to maintain the material, during active sensing operation, in at least two of the phases defining a boundary line (22) therebetween which is generally perpendicular to the longitudinal axis of the temperature gradient. The boundary line traverses longitudinally along the axis in response to changes in the oxygen partial pressure of the ambient atmosphere to which the sensing material is exposed. The sensor also includes a means (13,14;45,46) for furnishing an output signal in response to the traversal of the boundary line across a fixed detecting location of the sensing material in order to detect a specific pO2. <IMAGE></p> |
