Instrument for wire dia. measurement - has charge transfer detectors to determine moving wire dia. and is not susceptible to vibration or optical errors

摘要

An instrument is used to measure dynamically the dia. of a wire. It is not subject to errors due to optical effects on vibration of the moving wire. The instrument has a light source (1) which projects the shadow of a wire (2) onto a screen (3). Two linear photodetectors (4, 5) are located on the edge of the shadow on the screen. The detectors (4, 5) are charge transfer devices which may be considered as several aligned cells. Another detector (13) is used to measure the position of the wire (2) from the screen (3). A digital read-out is used to provide a numerical display related to the number of cells in the shadow detectors (4, 5) and the position of wire from the screen (3).