A load measuring system comprising a collar mounted between the two cables of the bridle on a sucker rod pump and a measuring device to determine the clamping force of the collar. When the cables are clamped together a pre-determined distance at an angle from the vertical, the load on the cables can be determined from the clamping force. The clamping force is measured by a strain gauge or other type of load cell. The load is measured and recorded at frequent intervals during the pump stroke, and by further analysis, critical operational parameters of the pump can be determined, and the information can be used to control the operation of the pump.