Abstract
In this paper developments towards a portable sensor system for the detection of benzene, toluene and xylene for screening are described. The monitoring system is based on the resonant photoacoustic technology. As light sources NIR laser diodes at wavelengths of overtone vibrations of the alkyl CH bonds are used. The resonator is of cylindrical shape with diameter 2R=5 cm and total length L=10 cm and is operated in its first azimuthal mode. The acoustical wave is detected by an electret microphone. Test measurements of water and toluene vapor are presented, For the detection of water vapor a 1.31 μm NIR laser diode was used. Water concentrations down to 0.5 mg/L in air could be measured. For the detection of toluene vapor a wavelength of 910 nm exciting the 3rd overtone vibration of the alkyl CH-bonds was used. At present the sensitivity is 3.2 mg/L.
| Original language | English |
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| Pages (from-to) | 69-72 |
| Number of pages | 4 |
| Journal | VDI Berichte |
| Issue number | 1366 |
| State | Published - 1998 |