# US 2019/0317002 A1 · Particle characterisation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0317002 A1 - Document ID: US20190317002A1 - Status: Published application - Kind: A1 - Application number: 16/414,961 - Filed: 2019-05-17 - Published: 2019-10-17 - Earliest claimed: 2015-09-23 - Assignees: Malvern Panalytical Limited - Applicants: Malvern Panalytical Limited - Inventors: Jason CORBETT; Alex MALM - Web page: https://patentgrep.com/patent/US20190317002A1 ## CPC - G01N 15/0211: {Investigating a scatter or diffraction pattern} - G01N 2015/0038: {Investigating nanoparticles} - G01N 2015/0053: {in liquids, e.g. trouble} - G01N 2015/0222: {from dynamic light scattering, e.g. photon correlation spectroscopy} - 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) ## Abstract Disclosed herein is a method of characterizing particles in a sample. The method comprises illuminating the sample in a sample cell with a light beam, so as to produce scattered light by the interaction of the light beam with the sample; obtaining a time series of measurements of the scattered light from a single detector; determining, from the time series of measurements from the single detector, which measurements were taken at times when a large particle was contributing to the scattered light; determining a particle size distribution, including correcting for light scattered by the large particle. ## Claims ### Claim 1 A method of characterising particles in a sample, comprising: illuminating the sample in a sample cell with a light beam, so as to produce scattered light by the interaction of the light beam with the sample; obtaining a time series of measurements of the scattered light from a detector; determining, from the time series of measurements from the detector, which measurements were taken at times when a large particle was contributing to the scattered light; determining a particle characteristic from the time series of measurements, including correcting for light scattered by the large particle; wherein correcting for light scattered by the large particle comprises determining a model of the background due to the large particle, and removing the model from the measurements. ### Claim 2 (depends on 1) The method of claim 1, further comprising determining a photon count rate signal from the time series of measurements. ### Claim 3 (depends on 2) The method of claim 2, wherein removing the model from the measurements comprises subtracting the model from the photon count rate to determine a corrected photon count rate, and determining a particle characteristic comprises determining a particle characteristic using the corrected photon count rate. ### Claim 4 (depends on 1) The method of claim 1, wherein determining a model of the background due to the large particle comprises filtering the photon count rate. ### Claim 5 (depends on 4) The method of claim 4, wherein filtering the photon count rate comprises low-pass filtering. ### Claim 6 (depends on 5) The method of claim 5, wherein the low-pass filter comprises a cut-off frequency of less than 10 Hz or less than 1 Hz. ### Claim 7 (depends on 4) The method of claim 4, wherein filtering photon count rate comprises determining a moving average of the photon count rate. ### Claim 8 (depends on 4) The method of claim 4, wherein filtering the photon count rate comprises using a Savitzky-Golay filter. ### Claim 9 (depends on 4) The method of claim 4, wherein filtering the photon count rate comprises using a digital IIR or FIR filter. ### Claim 10 (depends on 1) The method of claim 1, wherein the particle characteristic is at least one of a particle size distribution, an electrophoretic mobility, a magnetophoretic mobility, a molecular weight, an interaction parameter and a microrheological property. ### Claim 11 An apparatus for characterising particles comprising: a light source, a sample cell, a detector and a processor; wherein the light source is operable to illuminate a sample within the sample cell with a light beam so as to produce scattered light by interactions of the light beam with the sample; the detector is configured to detect the scattered light and produce a time series of measurements; the processor is configured to: receive the time series of measurements, and determine, from the time series of measurements, which measurements were taken at times when a large particle was contributing to the scattered light; determine a particle characteristic from the time series of measurements, including correcting for light scattered by the large particle; wherein correcting for light scattered by the large particle comprises determining a model of the light scattered by the large particle, and removing the model from the measurements. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the processor is configured to determine a photon count rate signal from the time series of measurements. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein removing the model from the measurements comprises subtracting the model from the photon count rate to determine a corrected photon count rate, and determining a particle characteristic comprises determining a particle characteristic using the corrected photon count rate. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein determining a model of the background due to the large particle comprises filtering the photon count rate. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein filtering the photon count rate comprises low-pass filtering. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the low-pass filter comprises a cut-off frequency of less than 10 Hz or less than 1 Hz. ### Claim 17 (depends on 14) The apparatus of claim 14, wherein filtering the photon count rate comprises determining a moving average of the photon count rate. ### Claim 18 (depends on 14) The apparatus of claim 14, wherein filtering the photon count rate comprises using a Savitzky-Golay filter. ### Claim 19 (depends on 14) The apparatus of claim 14, wherein filtering the photon count rate comprises using a digital IIR or FIR filter. ### Claim 20 (depends on 11) The apparatus of claim 11, wherein the particle characteristic is at least one of a particle size distribution, an electrophoretic mobility, a magnetophoretic mobility, a molecular weight, an interaction parameter, and a microrehological property.