Cylinder gauge measurement using a position sensitive detector.
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.
St John
W Doyle
WD
Department of Chemistry and Engineering Physics, University of Wisconsin-Platteville, USA. stjohn@uwplatt.edu
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