Patent ID: 8063373
Filing Date: 2011-11-22
Classification: G01N

Abstract:
1. A compact cavity ring down spectroscopy apparatus for detection and measurement of trace species in a sample gas, which comprises: a laser generating a laser beam which is provided as an intermittent laser beam; a ring down resonant cavity for holding a sample gas, said cavity receiving said intermittent laser beam and comprising at least two high-reflectivity mirrors, wherein said mirrors define a cavity length and one of said mirrors is a movable mirror; a drive attached to the mirror for moving the movable mirror to adjust the cavity length to achieve resonance between the intermittent laser beam and cavity modes; a photo-detector for receiving said intermittent laser beam from the cavity and for generating a voltage decay signal, thereby measuring an interaction of said sample with said laser beam, the voltage decay signal having noise; and a processor configured to receive the voltage decay signal, perform a box and whisker analysis if the noise is dominated by random sources, and perform a cluster analysis if the noise is dominated by systematic sources.