Patent ID: 8350581

Claim:
Apparatus for detecting changes in dielectric properties characteristic of aging in a polymer material having a cylindrical shape, comprising: a circuit comprising a capacitive probe configured to produce an electric field coupled with the polymer material, said capacitive probe engageable with a cylindrical inner-surface of the polymer material and comprising: a housing; at least one arm comprising a foot portion, an arcuate knee portion, and a forward portion, wherein said foot portion, said knee portion and said forward portion are integrally formed, wherein said at least one arm is pivotably mounted to said housing by a pivot in extending through an aperture of said knee portion, wherein said foot portion of said at least one arm is moveable in a first direction to move the corresponding forward portion from a first position in which said forward portion is fully contained within said housing to a second position in which said forward portion is radially displaced from said housing, and wherein said foot portion of said at least one arm is moveable in a second direction to move the corresponding forward portion from said second position to said first position; and a surface capacitor mounted to said forward portion; and an analyzer configured to analyze a response of said circuit to changes in the electric field resulting from the detection of aging characteristics in the polymer material.