Abstract
Ultraviolet (UV) and infrared (IR) radiation are used by most document examiners in the detection of alterations, erasures, substitutions, and secret writings; in the deciphering of charred or ancient documents; and in the viewing of obliterated text. The basic instrument used in conducting examinations of this sort is either the camera and photographic process or the electronic conversion tube. Most commercial equipment using these techniques has not been designed primarily for document examination but in most cases has been engineered for another purpose and then accommodated to document work. The purpose of the research reported in this paper was to use present-day technology to develop a system whereby the document examiner can conveniently take one, or, if desired, a hundred and one, questioned specimens and within a relatively short period of time observe the effects thereon of UV and IR radiation. To clarify the techniques used in this study, a few basic definitions and descriptions are being set forth.
