Patent ID: 8299449

Claim:
An apparatus for environmental monitoring, suitable for determination of mass concentration of air-dispersed particulate matter by means for collecting said particulate matter during a sampling period of an enrichment phase, based, on operating filters and spy filters, the spy filters not being exposed to the particulate matter, comprising: a pair of independent drawing lines each comprising a respective sampling head adapted to inlet air, and therefore particulate matter, into the apparatus; adjusting means for adjusting flow rate of said drawing lines; a sampling and measuring unit, comprising a filter housing and measuring arrangement for measuring the mass of particulate matter settled upon said operating filters, wherein the measuring arrangement means comprises a radiation emitter and a related detector, wherein the radiation emitted by said emitter is adapted to traverse the operating filters or spy filters and then be detected by said detector, the radiation emitter and the related detector implementing a β radiation attenuation technique; a rotary disc for moving said filter housing, adapted to bring said filters into a plurality of subsequent positions required for their loading, enriching, measuring and unloading; a movable arm for positioning said measuring arrangement with respect to said rotary disc to perform the measurements; a control unit configured to: (a) perform a blank measurement upon said operating filters, wherein β radiation flow through said operating filters is measured before said enrichment phase; (b) perform, contextually to the measurement in (a), the same measurement of the β radiation flow through said spy filters; (c) perform a measurement of the mass of particulate, settled on said operating filters exposed to said sampling period, also said measurement being performed through said β radiation attenuation technique; (d) perform, contextually to the measurement in (c), the same measurement on said spy filters; and (e) determine said mass concentration of particulate matter by correcting the mass measurement obtained with blank and particulate measurements performed upon the operating filters, with the measurements performed upon the spy filters.