The North American Philips G-M Counting Attachment for use with a Weissenberg camera was modified to achieve greater accuracy and speed in measuring integrated diffraction intensities. The shape, size and divergence of the primary beam was changed to obtain a larger and more reproducible number of counts. The oscillating mechanism was simplified and made more convenient. The receiving slit was enlarged so as to yield integrated intensities which were not affected by the diffraction peak shape. The accuracy and precision of the apparatus was determined by measuring the intensities of equivalent reflections from an ideally shaped crystal of nickel dimethyl glyoxime and by measuring the diffraction intensities from a parameterless structure such as sodium chloride. Very few calculation's are necessary in order to make the proper instrument settings as the necessary angles are read directly from a Weissenberg diffraction pattern.