Abstract: An apparatus for testing a tire. The tire has sidewalls and a tread portion. The tread portion has inner and outer surfaces. The apparatus comprises a tire lift. The tire lift has a main frame and a subframe. The subframe engages the main frame and is movable in a vertical direction. First and second drive rollers are operably connected to the subframe and arranged to support the tread portion. A stabilization roller is operably connected to the tire lift. The stabilization roller is arranged and configured to be placed proximal to one of the sidewalls. First and second electrodes are operably connected to the tire lift. The first and second electrodes are arranged and configured to be positioned on opposite sides of the tread portion. A power supply is arranged and configured to create an electrical potential between the first and second electrodes.

Abstract: An improved biased electrode (54) as used in a tire defect tester (12) is the subject of this patent application. The electrode (54) is movable between a first position located within a circle circumscribed by the beads (28) of a tire (26) being tested and a second position received in a cavity between the sidewalls (30) of the tire (26) in engagement with an underside of the tread portion (38) of the tire (26). The electrode (54) includes at least one, and, in a preferred embodiment, two, elongated member (72). The member (72) is pivotally mounted so that, as the electrode (54) is moved from its first to its second position, a first arm portion (80) will engage the underside of the tread portion (38) of the tire (26) and cause the element (72) to pivot so that it is in engagement with the underside of the tread portion (38) substantially along the length of the element (72).