| abstract |
PCT No. PCT/GB95/01979 Sec. 371 Date Feb. 20, 1997 Sec. 102(e) Date Feb. 20, 1997 PCT Filed Aug. 21, 1995 PCT Pub. No. WO96/06346 PCT Pub. Date Feb. 29, 1996The presence of Semtex plastic explosive in a sample such as a fingerprint is detected by Raman spectroscopy. RDX and PETN, the active chemical ingredients of Semtex, have strong Raman peaks at 885 cm-1 and 874 cm-1 respectively. Consequently, both these peaks can be detected in a Raman spectroscopic system by employing a filter having a narrow passband centered on 880 cm-1 and with a bandwidth of 20 cm-1. Such a filter is used in a Raman system used to scan airport boarding cards, or in a Raman microscope which produces images of fingerprints. |