Accuracy in film-scanner intensity measurements

The accuracy in X-ray diffraction intensities obtained by the use of an automatic IBM 1800-controlled SAAB film scanner is discussed. The random errors have been found to be around 4% of the intensities for most reflexions. By comparison with data obtained from a Joyce-Loebl microdensitometer it has been found that there are no serious systematic errors in the film-scanner data. Measurements from Weissenberg and precession films are discussed.