A simple interferometer comprised of two glass plates and a frame for changing the angle between the plates is described for the determination of the measurement errors of an autocollimator. The interferometer is useful in that it generates angles which are measured with an autocollimator and allows the values of these angles to be determined by counting the passage of multiple beam interference fringes. The instrument is easy to use and is very insensitive to both thermal gradients and vibration. The sensitivity of the interferometer depends upon the wave‐length and the distance from the wedge apex to the point at which the fringes are observed and, for this instrument, can be varied from about 1 to 3″/fringe. For the particular location at which the fringes were observed in this experiment, the sensitivity of the interferometer is 1.429±0.004″/fringe. Typical percentage errors obtained in measurements of three autocollimators varied from 0.2 to 1.0% over a range of 285.8″.

1.
T. J.
O’Donnell
,
Amer. Machinist Spec. Rep.
No.
490
,
142
(
1960
).
Google Scholar
 
2.
F. A. Jenkins and H. E. White, Fundamentals of Physical Optics (McGraw‐Hill Book Co., New York, 1937), p. 89.
3.
S. Tolansky, Multiple Beam Interjerometry (Oxford University Press, London, 1949).
This content is only available via PDF.
© 1968 The American Institute of Physics.
1968
The American Institute of Physics
You do not currently have access to this content.