US Patent 7346971 Blind rivet monitoring system supply pressure compensation

A rivet set quality monitoring system is disclosed. A supply pressure sensor monitors the supply pressure to the tool. The tool has a second sensor which monitors strains or loads associated with a rivet set event. A processor evaluates outputs from the pressure sensor to apply a scaling factor to the output of the second sensor which is a function of the output of the pressure sensor. This modified data is analyzed to determine if the rivet set is acceptable.