A composite steering column jacket including a pair of composite sections joined along a flange area. Infrared light transmitting filters 3 that allow infrared light to pass therethrough and cut off visible light are provided in respective paths of light entering the optical sensors 2. The carrier body 10 is provided with a bar code 20 which relates to the material and dimensions of the blank 13 and may identify data according to which the blank 13 is to be worked The bar code 20 is adapted to be changed by the working machine so as to prevent the carrier body 10 from being reused with the same or a different blank 13. If the component is a metallic oxide semiconductor field effect transistor, the system calculate absolute a linear distance and a trace distance between a source pin of the MOSFET and a capacitor pin of a coupling capacitor connected to the source pin.