IN USING THIS TECHNIQUE, A LASER BEAM IS FOCUSED INTO A CELL CONTAINING A GAS SAMPLE OF INTEREST. IF CERTAIN GAS SAMPLE CONSTITUENTS ABSORB THIS RADIATION, THE GAS WILL HEAT UP, THEREBY PRODUCING AN INCREASE IN PRESSURE WHICH CAN BE DETECTED BY A SENSITIVE MICROPHONE. UTILIZING BOTH CARBON DIOXIDE AND CARBON MONOXIDE LASERS, THIRTY-NINE WAVELENGTHS IN THE 6, 9, AND 11 MICROMETER SPECTRAL REGIONS OF THE INFRARED WERE SCANNED. NINE EXPLOSIVES WERE INVESTIGATED AT A VARIETY OF AVAILABLE WAVELENGTHS. IN THE 6 MICROMETER REGION, STRONG INTERFERENCE BY WATER VAPOR MADE THE SENSITIVE DETECTION OF EXPLOSIVES VAPORS INFEASIBLE. IN THE 9 AND 11 MICROMETER REGIONS, INTERFERENCES WERE SUBSTANTIALLY REDUCED, AND CERTAIN EXPLOSIVE VAPORS COULD BE SENSITIVELY DETECTED. ADDITIONAL MEASUREMENTS ARE RECOMMENDED TO VERIFY THAT THE TECHNIQUE HAS A PARCTICAL FEASIBILITY. (AUTHOR ABSTRACT)