Associate professor, Materials Division and director of Electron Microanalysis Laboratory, Rensselaer Polytechnic Institute, Troy, N.Y.
research engineer, IBM Research Laboratory, San Jose, Calif.
Captain, New York State Police Bureau of Criminal Investigation and director, New York State Police Scientific Laboratory, Albany, N.Y.
(Received 4 March 1972; accepted 7 June 1972)
At present, characterization of topography of paint fragment samples in criminal cases is being undertaken by use of light microscopy. Wet chemical analysis and a wide range of spectral techniques are being used for elemental identification. Electron optical instruments have been developed that are capable of both topographical and elemental analyses. For example, the scanning electron microscope (SEM) can provide topographical information with greater depth of focus, higher magnification, and higher resolution than optical microscopy. Additionally, the electron beam can be used to excite characteristic X-radiation from the sample, theleby providing a wavelength spectrum for elemental identification and chemical species distribution in the sample.
Paper ID: JFS10155J