Parkhurst & Oliff
Oxygen sensor
 An oxyen sensor for determining an oxygen partial pressure of a measurement gas in a measurement-space, comprising (a) an elongate oxygen sensing element having an oxygen detecting portion adjacent to its one longitudinal end, (b) a first protective covering for protecting at least an end portion of the sensing element which is located within the measurement-space and exposed to the measurement gas and which includes the oxygen detecting portion; (c) a second protective covering for covering another portion of the sensing element which is not exposed to the measurement gas; and (d) a retainer housing for supporting the sensing element, and the first and second protective coverings such that the end portion of the sensing element having the detecting portion is located within the conduit. The first and second protective coverings consist of an integral protective tubing member which is supported by the retainer housing with fluid tightness therebetween and which accommodates the oxygen sensing element. The oxygen sensor may comprise an air-tight mass of an inorganic particulate material which fills a portion of a space defined by the periphery of the sensing element and the inner surface of the protective tubing member, over a predetermined length along the axis of the protective tubing member. 
NGK Insulators, Ltd.
G
G01N
inventional
Nobuhide Takao
Kato Murase