An Instrument for Measuring Broad-Line Spectrograms
E. G. Ebbighausen · Publications of the Astronomical Society of the Pacific · 1962
In recent years a number of devices have been developed for measuring the position on a plate of broad-line features such as interference fringes and spectral lines with greater accuracy than can be obtained by direct visual setting with a fiducial line.References to some of the pertinent literature are given at the end of this article.A description of such an instrument designed by the writer and constructed at the University of Oregon is presented here.The design of these instruments falls into two basic types.In one type, the image of a filament, much reduced in width, is