A single-crystal orientation technique using doubly exposed Weissenberg photographs

A new technique to determine the orientation of a single-crystal is presented. The technique utilizes two screenless Weissenberg oscillation photographs taken in the same crystal oscillation range but with different film-translation-to-crystal-oscillation gear ratios. The technique is especially useful for small-molecule single-crystal data-collection systems using an imaging plate as an area detector. A program system was written and successfully applied to an imaging-plate diffractometer (IPD-WAS) designed for studying phase transitions in the crystalline state.