RESUMEN
The design and certain basic characteristics of a new type of optoacoustic device (cell) are described. Initial experimental data using a CO(2) laser operating in the 9-10-microm wavelength region demonstrated sufficient sensitivity to measure the absorption due to SF(6) in the air at a concentration of one part in 10(11). Acoustic Q's were demonstrated in excess of 1800. The general expression for the optoacoustic pressure variations inside the acoustical resonant cavity is given.
RESUMEN
The direct detection of nitroglycerine, ethylene glycol dinitrate, and dinitrotoluene by optoacoustic spectroscopy techniques at 6 microm, 9 microm, and 11 microm is reported. The effect of interference by normal atmospheric pollutants is investigated, and it is found that of those wavelengths used in this investigation the 9-microm and 11-/microm spectral regions, using a CO(2) laser as radiation source, are the most promising for use in explosive detection.