Autocollimator

An autocollimator is an optical instrument for non-contact measurement of angles. They are typically used to align components and measure deflections in optical or mechanical systems. An autocollimator works by projecting an image onto a target mirror, and measuring the deflection of the returned image against a scale, either visually or by means of an electronic detector. A visual autocollimator can measure angles as small as 0.5 arcsecond, while an electronic autocollimator can be up to 100 times more accurate.

Visual autocollimators are often used for lining up laser rod ends and checking the face parallelism of optical windows and wedges. Electronic and digital autocollimators are used as angle measurement standards, for monitoring angular movement over long periods of time and for checking angular position repeatability in mechanical systems. Servo autocollimators are specialized compact forms of electronic autocollimators that are used in high speed servo-feedback loops for stable platform applications.

ee also

*Autocollimation
*Collimator

References

*cite web | author=Lowell, Tom| year=| title=Small Angles and Autocollimators | format=HTML | work=Vermont Photonics | url=http://www.vermontphotonics.com/articles/smallanglesautocoll.html | accessdate=2006-05-07
*cite web | author=Morel, Jerrat| year=| title=Principles of Operation | format=HTML | work=Micro-Radian Instruments | url=http://www.micro-radian.com/Principles.html | accessdate=2007-05-14