A method and apparatus for determining and displaying signal quality measurement on a television display screen. The training image and the target image are elements of a sequence of images. During use, the plug is delivered into a passage through tissue over a guide wire. The method further includes counting periodic human motions appropriate to the current user activity. The heat exchanger includes a container defining a coolant depot adjacent to and in heat exchange relation with the flow channel and adapted to contain a coolant to accept heat rejected by the components when coolant is not flowing in the coolant channel between the inlet and the outlet. The system and the method may be utilized to reduce the repair cycle time for a railcar so that a railcar may be repaired quickly, inexpensively, and efficiently.