This study concerns remote detection of alcohol vapors in cabins of moving vehicles. By means of a simplified description of propagation of two combined laser beams differently absorbed in alcohol vapors and in vehicle windowpanes, difficulties in detecting alcohol vapors in vehicle cabins using classical differential absorption method are demonstrated. Unreported in the literature, this method of remote detection of alcohol vapors in the air exhaled by a driver or a passenger in moving vehicles is proposed. The method uses two combined laser beams that illuminate different zones in the car cabin through the same windowpane. Based on the correlation between the spread of the transmission of these zones and the alcohol concentration in the air exhaled by a drunken person, it is possible to determine if the alcohol exists in the exhaled air. The effectiveness of the presented method is confirmed experimentally.
Over recent years, there has been increasing use of cascade lasers and multi-pass cells in optical systems detecting the gaseous atmospheric pollutants and measuring the gas concentrations.
The paper presents the use of a tunable quantum cascade laser as a source of the IR radiation in an advanced detection system enabling the trace gaseous atmospheric pollutants to be identified. Apart from the laser, the main elements of the system are: a multi-pass cell, an IR detector and a module for control and analysis. Operation of the system is exemplified by measuring the level of the air pollution with ammonia, carbon oxide and nitrous oxide.
The aim of the work was the characterization and classification of certain types of plant pollens by using laser optical methods, which were supported by the chemmometrics. Several species of pollen were examined, for which a database of spectral characteristics was created, using LIF, Raman scattering and FTIR methods. Spectral database contains characteristics of both common allergens and pollen of minor importance. Based on registered spectra, statistical analysis was made, which allows the classification of the tested pollen species.
For the study of the emission spectra Nd:YAG laser was used with the fourth harmonic generation (266 nm) and GaN diode laser (375 nm). For Raman scattering spectra spectrometer Nicolet IS-50 with a excitation wavelength of 1064 nm was used. The FTIR spectra, recorded in the mid infrared1 range (4000-650 cm-1) were collected with use of transmission mode (KBr pellet), ATR and DRIFT.
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