Patent ID: 8445850

Claim:
An open-path optical sensor, comprising: a source assembly, said source assembly emitting UV radiation corresponding to a signal channel and a reference channel; a detector assembly for receiving UV radiation emitted by said source assembly, said detector assembly comprising (i) a first detector for detecting UV radiation corresponding to the signal channel, (ii) a second detector for detecting UV radiation corresponding to the reference channel, and (iii) a data acquisition system in communication with said first detector and said second detector; a plurality of reflectors for directing UV radiation emitted by said source assembly to said detector assembly, each of said reflectors being positioned at one end of a different monitoring path, said detector assembly being positioned at the other end of each monitoring path; and a positioning device, said source assembly and said detector assembly being mounted on said positioning device, wherein said positioning device is capable of reorienting said source assembly and said detector assembly between the monitoring paths; wherein said first detector comprises a band-pass filter for rejecting UV radiation outside of the signal channel; wherein said second detector comprises a band-pass filter for rejecting UV radiation outside of the reference channel; wherein said data acquisition system calculates the ratio of (i) the intensity of the UV radiation corresponding to the signal channel to (ii) the intensity of the UV radiation corresponding to the reference channel; wherein the signal channel is a wavelength or range of wavelengths between about 170 nanometers and 230 nanometers; and wherein the reference channel is a wavelength or range of wavelengths between about 260 nanometers and 300 nanometers.