# US 9,752,983 B2 · Optical density monitor and comparator systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,983 B2 - Document ID: US9752983B2 - Status: Granted - Kind: B2 - Application number: 14/271,859 - Filed: 2014-05-07 - Published: 2014-08-28 - Granted: 2017-09-05 - Earliest claimed: 2011-06-17 - Assignees: AquiSense Technologies LLC; The University of North Carolina at Charlotte - Applicants: The University of North Carolina at Charlotte; AquiSense Technologies LLC - Inventors: Jennifer Godwin Pagan; Edward Brittain Stokes; Paolo Batoni - Web page: https://patentgrep.com/patent/US9752983B2 ## CPC - G01N 21/5907: {Densitometers} - A61L 9/205: {using a photocatalyst or photosensitiser} - G01N 21/031: {Multipass arrangements} - G01N 21/33: using ultraviolet light (G01N21/39 takes precedence) - A61L 2209/11: Apparatus for controlling air treatment - C02F 1/32: with ultraviolet light - C02F 2209/11: Turbidity - C02F 2303/04: Disinfection - G01N 2201/065: Integrating spheres - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract The present disclosure relates generally to systems and methods for determining the absorption coefficient and the optical density of a fluid as they relate to the wavelength of incident radiation. Specifically, ultraviolet light-emitting diodes (UV LEDs) or the like that emit ultraviolet (UV) radiation or the like are used as sources for irradiating the interior of an integrating chamber that is designed to increase the path length of the radiation through the fluid, thus enhancing the detection limits of the absorption coefficient and the optical density according to Beer's Law. ## Claims ### Claim 1 A system for determining the absorption coefficient and/or the optical density of a fluid and/or organic/inorganic particles disposed in the fluid, comprising: an integrating flow cell configured to contain a fluid sample within substantially an entire interior portion thereof; one or more point radiation sources disposed about an interior periphery of the integrating flow cell, wherein the one or more point radiation sources are operable for delivering radiation of a predetermined wavelength to the fluid sample; and one or more radiation detectors operable for detecting radiation within the interior portion of the integrating flow cell; wherein the integrating flow cell comprises an integrating sphere having an interior surface operable for reflecting the radiation delivered to the fluid sample by the one or more point radiation sources such that a radiation intensity is uniform throughout the interior portion of the flow cell; and wherein a path length of the radiation delivered to the fluid sample and reflected is maximized by the fluid sample occupying substantially the entire interior portion of the integrating flow cell. ### Claim 2 (depends on 1) The system of claim 1, wherein the absorption coefficient and/or the optical density of the fluid and/or organic/inorganic particles disposed in the fluid is determined utilizing the predetermined wavelength of the delivered radiation and a characteristic of the detected radiation. ### Claim 3 (depends on 1) The system of claim 1, wherein the determined absorption coefficient and/or optical density of the fluid and/or organic/inorganic particles disposed in the fluid is measured at one or more predetermined wavelengths of delivered radiation and a ratio of measured values is used to identify the fluid and/or organic/inorganic particles disposed in the fluid. ### Claim 4 (depends on 1) The system of claim 1, wherein the one or more point radiation sources comprise a first point radiation source operable for delivering radiation of a first predetermined wavelength to the fluid sample. ### Claim 5 (depends on 4) The system of claim 4, wherein the one or more point radiation sources further comprise a second point radiation source operable for delivering radiation of a second predetermined wavelength to the fluid sample. ### Claim 6 (depends on 1) The system of claim 1, wherein the one or more point radiation sources comprise one or more ultraviolet (UV) point radiation sources and/or one or more visible point radiation sources. ### Claim 7 (depends on 1) The system of claim 1, wherein the one or more point radiation sources comprise a point radiation source operable for delivering radiation having a predetermined wavelength of between about 260 nm and about 280 nm to the fluid sample. ### Claim 8 (depends on 1) The system of claim 1, wherein the one or more point radiation sources comprise one or more semiconductor optical sources, light-emitting diode (LED) optical sources, and ultraviolet (UV) optical sources. ### Claim 9 A method for determining the absorption coefficient and/or the optical density of a fluid and/or organic/inorganic particles disposed in the fluid, comprising: providing an integrating flow cell configured to contain a fluid sample within substantially an entire interior portion thereof; providing one or more point radiation sources disposed about an interior periphery of the integrating flow cell, wherein the one or more point radiation sources are operable for delivering radiation of a predetermined wavelength to the fluid sample; and providing one or more radiation detectors operable for detecting radiation within the interior portion of the integrating flow cell; wherein the integrating flow cell comprises an integrating sphere having an interior surface operable for reflecting the radiation delivered to the fluid sample by the one or more point radiation sources such that a radiation intensity is uniform throughout the interior portion of the flow cell; and wherein a path length of the radiation delivered to the fluid sample and reflected is maximized by the fluid sample occupying substantially the entire interior portion of the integrating flow cell. ### Claim 10 (depends on 9) The method of claim 9, wherein the absorption coefficient and/or the optical density of the fluid and/or organic/inorganic particles disposed in the fluid is determined utilizing the predetermined wavelength of the delivered radiation and a characteristic of the detected radiation. ### Claim 11 (depends on 9) The method of claim 9, wherein the determined absorption coefficient and/or optical density of the fluid and/or organic/inorganic particles disposed in the fluid is measured at one or more predetermined wavelengths of delivered radiation and a ratio of measured values is used to identify the fluid and/or organic/inorganic particles disposed in the fluid. ### Claim 12 (depends on 9) The method of claim 9, wherein the one or more point radiation sources comprise a first point radiation source operable for delivering radiation of a first predetermined wavelength to the fluid sample. ### Claim 13 (depends on 12) The method of claim 12, wherein the one or more point radiation sources further comprise a second point radiation source operable for delivering radiation of a second predetermined wavelength to the fluid sample. ### Claim 14 (depends on 9) The method of claim 9, wherein the one or more point radiation sources comprise one or more ultraviolet (UV) point radiation sources and/or one or more visible point radiation sources. ### Claim 15 (depends on 9) The method of claim 9, wherein the one or more point radiation sources comprise a point radiation source operable for delivering radiation having a predetermined wavelength of between about 260 nm and about 280 nm to the fluid sample. ### Claim 16 (depends on 9) The method of claim 9, wherein the one or more point radiation sources comprise one or more semiconductor optical sources, light-emitting diode (LED) optical sources, and ultraviolet (UV) optical source.