Abstract
Keywords:
air quality (AQ) monitoring, Remote optical measurement techniques (ROMTs), NDIR (Non-Disperse Infrared), DOAS (Differential Optical Absorption Spectroscopy), short term spectra correlation coefficients.
Abstract
The paper relates to the experience and results from a range of over 120 days of air quality monitoring campaigns in the Romanian city of Timisoara, achieved in cross roads, industrial areas, and in parks. Air quality measuring is still very new and less experienced in Eastern European countries. Nevertheless, the University of Timisoara undertakes on line experiments in urban areas, using measuring methods, in accordance to the national legislation (point source measurement), but also remote controlled open path techniques. In the frame of this paper only results concerning the CO pollutants will be analyzed. CO - concentrations were measured simultaneously in several places, using two different specialized instruments: a HORIBA device which furnishes the local pollution level, representing the classic method, and a SIEMENS open path instrument delivering the average values of CO-concentrations on a distance of 10 – 50 m, representing an open path optical instrument. Taking into account the random character of the CO-concentration signals, statistical tools like correlation, are suitable methods for data analysis. However, a problem arises since the CO-concentration signals, on one side, and the traffic and meteorological parameters, on the other, are sampled with different frequencies. This problem can be overcome using the short time spectral analysis of the pollution signals.