SO2 FLUX MEASUREMENTS AT MT. ETNA USING A CORRELATION SPECTROMETER COSPEC AND A NEW REAL-TIME ELABORATION SYSTEM

T. Caltabiano (Istituto Internazionale di Vulcanologia - CNR Piazza Roma, 2 - 95123 CATANIA, Italy)

A new system of acquisition and elaboration has recently been developed for data that are systematically acquired with a correlation spectrometer COSPEC on the SO2 flux of active Sicilian volcanoes and in particular Mt. Etna. The COSPEC is connected to a portable Personal Computer that uses an A/D (analog-to-digital) conversion card to collect the signals from the spectrometer. A GPS system gives the information on the geographic position during the measurements. This system allows the real-time measurement of SO2 flux data corrected both for the scanning path-way and noise induced by eventual interference. During the measurements this system constantly shows the SO2 concentration present in the field of view of the spectrometer and the value of the SO2 flux calculated up to that point of the scan. The user-system interface has been designed to make the use of the system as easy and as friendly as possible and to avoid eventual operator errors. This acquisition system, easily transportable and extremely compact, immediately gives the data already elaborated and is thus very useful in the monitoring and prediction of volcanic activity. In this work the tests used to set up the system carried out on Mt. Etna are presented.