Patent ID: 8912784

Claim:
A conductive member valuator, comprising: a cylindrical or spherical first electrode which has contact with an outer circumferential face of a roller-like conductive member rotating about a shaft center, and configured to rotate in a direction opposite the conductive member; a second electrode which is connected to the shaft center of the conductive member; a voltage applier configured to apply evaluation voltage including at least an AC component between the first electrode and the second electrode; a current value measuring device configured to measure a current value flowing between the first electrode and the second electrode when the evaluation voltage is applied by the voltage applier; an extreme value obtaining device configured to obtain at least one value amongst a maximum value and a minimum value in one cycle of the AC component included in the current value from the current value measured by the current value measuring device; and an evaluation device configured to evaluate the conductive member based on said at least one value obtained by the extreme value obtaining device, wherein the evaluation device is configured to calculate a difference value between the maximum value and the minimum value, in a predetermined evaluation period, obtained by the extreme value obtaining device, and evaluate the conductive member based on a result in which the difference value is compared to a previously defined standard difference value.