| 摘要 |
A scanning apparatus and method for determining the wall thickness of a travelling electrical cable formed in an extrusion process with a cable core being coated by the wall material, having a source for emitting a discrete beam of radiation such as x-rays or beta particles of sufficient energy to penetrate at least the wall of said cable. A suitable radiation detector is then positioned to receive the beam and provide output signals representative of the amount of radiation received thereby. A movable support carries the source and the detector as to cause the beam to scan the cable with means responsive to the output signals from the detector determining the amount of radiation absorbed by the cable as the beam scans the cable. Since the discrete beam of radiation has sufficient energy only to penetrate the wall of the cable and not the core, a measure may therefore be provided of the cable wall thickness. <IMAGE> |
