The AC2 is considered as a quality assurance unit or system which is in accordance to the relative measurement of the reference surface. It combines a floating system which touches on the parts of the device to be joint through the use of a rivet. The AC2 machine is also the same as the AC1 version wherein the position or riveting distance of the latter can be dome by taking into account the last height result of the rivet. It may also be used obtain results of the riveted head height. In this way sufficient, information is supplied in order to accept or reject the part.