title: Cylinder gauge measurement using a position sensitive detector.
abstract: A position sensitive detector (PSD) has been used to determine the diameter of cylindrical pins based on the shift in a laser beam's centroid. The centroid of the light beam is defined here as the weighted average of position by the local intensity. A shift can be observed in the centroid of an otherwise axially symmetric light beam, which is partially obstructed. Additionally, the maximum shift in the centroid is a unique function of the obstructing cylinder diameter. Thus to determine the cylinder diameter, one only needs to detect this maximum shift as the cylinder is swept across the beam.
authors.affiliation: Department of Chemistry and Engineering Physics, University of Wisconsin-Platteville, USA. stjohn@uwplatt.edu
authors.forename: W Doyle
authors.initials: WD
authors.lastname: St John
mesh_terms: D004566:Electrodes; D004867:Equipment Design; D007834:Lasers; D046529:Microscopy, Electron, Transmission; D015233:Models, Statistical; D008962:Models, Theoretical; D016011:Normal Distribution; D055095:Optics and Photonics; D012107:Research Design; D013055:Spectrophotometry, Infrared / Q000379:methods