Apparatus for non-destructively testing a polymeric cylindrical object to measure aging characteristics includes a source of electrical energy, a monitoring device, a probe for engaging an inner surface of the cylindrical object, and a conductor connecting at least the source of electrical energy and the probe, the probe comprising contact portions having object engaging surfaces including capacitor circuitry thereon. The probe further includes a nose portion having recesses disposed about the circumference within which the contact portions are housed, the nose portion being engagable with an inner surface of the cylindrical object and the object engaging surfaces being movable between a first position in which the object engaging surfaces are housed entirely within recesses and a second position in which the object engaging surfaces are deployed away from the nose portion.