METHOD AND APPARATUS FOR MEASUREMENTS OF LUMINOUS ISOTROPIC RADIATION AS OBTAINED BY MEANS OF LASER SPECTROSCOPY TECHNIQUES, IN PARTICULAR FOR SUB- MICROMETRIC PARTICULATE MEASUREMENTS

摘要

The invention concerns a method for the measurement of the spectrum of isotropic luminous radiation of a gas excited by a laser light, utilizing an apparatus comprising at least a transparent measurement chamber (41 ), and performs the following steps: A. Making said gas pass in said at least a measurement chamber (41); B. Sending a laser beam (21) on said gas in said at least a measurement chamber (41 ). The method uses an integrating sphere (42) substantially enclosing said at least a measurement chamber (41), as well as one or more photo - detectors for measuring the luminous signal collected by the integrating sphere. Before step A a calibration step is performed and, subsequently to step B, the following further steps are performed: C. collecting the light diffused by said gas hit by said laser beam (21 ), by means of said integrating sphere (42), thus obtaining a measurement luminous signal; D. transforming the measurement luminous signal into an electrical signal by means of suitable photo - detectors; E. analysing said electric signal in order to obtain the measurement of the gas spectrum. The invention further concerns a measurement apparatus implementing the method according to the invention.