Patent ID: 6593573
Filing Date: 2003-07-15
Classification: F02B,G01N

Abstract:
An apparatus for monitoring the distribution within a defined space of a chemical species, wherein a plurality of radiation sources and radiation detectors are distributed around the perimeter of the space such that beams of radiation are emitted across the space and radiation from each source is directed along a predetermined path towards at least one detector, the sources emit radiation at a wavelength selected to excite vibrational and/or rotational transitions in at least one of the chemical species such that radiation is absorbed to a greater degree by the said at least one species than by at least one other species, absorption of the radiation occurring along each of the predetermined paths is monitored to provide a measure of the path integral of the concentration of the said at least one species along each path, and a representation of the distribution of the concentration of the said at least one species within the space is derived from the measured path integrals of concentration.