A sensor assembly and method are described for calibrating a tensioning system. A first movement of a slack arm of the tensioning system may be identified. It may be determined that the slack arm has been maintained in a first calibration position for a first predetermined time interval, and a first calibration setting for the slack arm may be determined based upon the first calibration position. A second movement of a slack arm of the tensioning system may be identified. It may be determined that the slack arm has been maintained in a second calibration position for a second predetermined time interval, and a second calibration setting for the slack arm may be determined based upon the identified second calibration position.
