HIGH-PRECISION METHOD AND APPARATUS FOR IN-SITU CONTINUOUS MEASUREMENT OF CONCENTRATIONS OF GASES AND VOLATILE PRODUCTS

摘要

ABSTRACT OF THE DISCLOSURE:Continous monitoring of variations in the concentrationsof individual components in gaseous mixtures such as, moreparticularly, gases released from volcanic vents, is achievedin the field with consistently high precision, namely about2 ppm, over extended periods of time, while the time lag fordetecting a variation is minimized. On-site measurements aremade with a portable apparatus, comprising a sampling probefrom which the gas is led to an expansion enclosure maintainedat a regulated pressure of about 10-2 to 10-1 millibar. Fromthis enclosure, the gas is metered by means of a piezoelectricvalve into the analysing chamber of a quadrupole mass-spectrometerSeveral units operating in the field, directly over the volcanicvents, may be connected to a central date processing station,so as to derive useful correlations for predicting futurevolcanic activity, for monitoring geothermal sources, and fordetecting gas-release anomalies for purposes of geophysicalexploration.