Autocollimator, Electro-Optical, High Resolution
Wednesday, August 30, 2006
A High Resolution Electro Optical Autocollimator has been designed and developed that uses the same LED’s and CCD array for each axis. The focal length of the optics is 1100 mm. The Optical components and photodetector arrays are mounted on a ceramic base plate providing increased mechanical integrity and thermal stability.
Measuring angles, as small as 0.005 arc-sec can be achieved, but only under ideal lab conditions. All specifications stated below assume a stable environment without excessive vibration or air movement. There are no provisions for an adjustable mounting base because of the wide measuring range of 300 arc-sec. Inaccuracies, due to drift, could be introduced by any form of base plate adjustment screws so none are available. The Autocollimator adjustments are made using ceramic blocks and ceramic shims.
Stability, which is related to repeatability and drift with time, can be achieved as follows: ‘The instrument will achieve stability specifications after a 24-hour soaking period in a stabilized laboratory environment, followed be a 60-minute warm-up period. During warm-up, the instrument will be fully functional but may exhibit slightly greater drift characteristics than specified’.
Specifications are as follows: Resolution: 0.005”; Measuring Range: 300”; Signal Acquisition Range: 600” Reproducibility of a reading: 0.01”; Aperture: 50 mm Accuracy: over 300”, +/-0.06”; over 40”, +/-0.04”; over 10”, +/-0.02” Min Aperture: 13 mm (0.5 in); Working Distance: 4 m (12 ft) Weight: 20 kg (44 lbs).
Source: Mollor-Wedel, Elcomat Model HR, Marketing Literature; Vermont Photonics Inc., Putney, Vermont, Ph 1-802-387-5201 Reference: “Optical Alignment”, by Thomas H. Thurston, SPIE Proceedings, Volume 251, 1980,
Industrial Products
posted by JD52 @ 8:08 PM,
