Rapid alignment of crystals in x-ray cameras

The misalignment in the setting of a crystal in the Weissenberg goniometer is determined from the measurement of the displacement of the spots from the central line at θ=±45° with the arcs set in the parallel-perpendicular position (Hendershot, 1937) or in the 45° position (Davis, 1950). When reflections are not present at θ=±45° a graphical straight line method has been suggested by Garaycochea et al. (1961). Another graphical method called the "Ellipse method" suggested in the paper does not involve too much calculation after the measurement and hence is easy in application, accurate in the determination of errors and economical in time. © 1964 Indian Academy of Sciences.