and deflection channels for isolating for example every fifth workpiece 701 for testing the isolated workpiece 701 is picked up by a carrier device 706 which slides on guides 707 and which has a gripper member 709 for picking up the workpiece 701 and for depositing it onto the measurement plane 601 the computer system 1 controls the two arms 2 to perform the dimensional measurement and then evaluates if the detected tolerances are acceptable or not if positive the workpiece 701 is carried back by the device 706 onto the conveyor 700 to continue towards the region 703 if negative the workpiece 701 is on the other hand carried on a conveyor 715 towards a region 716 for collection of reject workpieces the entire operation described is controlled by the computer system 1 and due to the presence of the two arms 2 which operate simultaneously there is a drastic reduction in the measurement time which can be of the order of a minute so that the measurement system can be combined with a production line producing several hundreds of workpieces per hour with statistical dimensional measurement since as mentioned the computer system 1 can also act on the production process for the prevention of rejects the configurations of the measurement system formed according to the present invention can be significantly different from one another both as far as the number and the arrangement of arms is concerned and as far as the individual arms are concerned by the presence or absence of axes of rotation and.