Procedure and apparatus for the measurement of small relative displacements between two bodies. (Machine-translation by Google Translate, not legally binding)

摘要

Method and apparatus for measuring small relative displacements between two bodies, characterized in that the method consists of moving along a rectilinear path over a distance capable of being permanently measured a mobile equipment carrying at least one photoelectric assembly comprising a source luminous and a photosensitive cell coupled in such a way that successively a witness belonging to the first body and a witness belonging to the second one interpose in the source-cell light path and, by the signal resulting from the first concealment, start the measuring device of the distance and by the signal resulting from the second stop this measurement. (Machine-translation by Google Translate, not legally binding)