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A multivariate statistical method has been applied to apportion the atmospheric pollutant concentrations measured by automatic gas analyzers placed on a mobile laboratory for air quality monitoring in Taranto (Italy). In particular, Principal Component Analysis (PCA) followed by Absolute Principal Component Scores (APCS) technique was performed to identify the number of emission sources and their contribution to measured concentrations of CO, NOx, benzene toluene m+p-Xylene (BTX). This procedure singled out two different sources that explain about 85% of collected data variance.

The design of a fast, versatile multichannel scaler-analyzer system is described here. This system is especially suitable for clinical measurements in real time from multichannel nuclear sources characterized by single or multiple isotopes. The instrumentation characteristics are as follows: 1) The system is programmable and modular, with 16 channels maximum per module. The active channels can be selected. The channel scanning time depends upon the selected system configuration. 2) The true acquisition phase is autonomous. The acquired data are transferred from the instrumentation to the master computer under interrupt control. 3) The system is constructed from commercially available components. Their high integration and speed have led to powerful, compact, flexible instrumentation while containing cost.