Abstract: An apparatus for measuring torque in a rotary encoder between the encoder body and encoder shaft. The apparatus includes a rotary stage for mounting and rotating the body of the rotary encoder, a probe arm having a first end for engaging the shaft of the rotary encoder in a stationary position, and a force sensor mourned on an adjustable assembly. The adjustable assembly enables the force sensor to be placed in contact with a second end of the probe arm, such that the plane of the force sensor is parallel to a plane defined by the vertical center plane of the probe arm passing through an axis of rotation of the shaft of the rotary encoder. By rotating the encoder body at a constant speed in clockwise and counterclockwise directions and measuring torque at regular time intervals, the range of torque, torque grittiness, and torque hysteresis may be determined.