# US 10,119,910 B2 · Particle characterisation instrument > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,910 B2 - Document ID: US10119910B2 - Status: Granted - Kind: B2 - Application number: 14/879,820 - Filed: 2015-10-09 - Published: 2017-04-13 - Granted: 2018-11-06 - Earliest claimed: 2015-10-09 - Assignees: Malvern Panalytical Limited - Applicants: Malvern Instruments Limited - Inventors: Jason Cecil William Corbett - Web page: https://patentgrep.com/patent/US10119910B2 ## CPC - G01N 21/64: Fluorescence; Phosphorescence - G01J 3/4406: {Fluorescence spectrometry} - G01N 15/0211: {Investigating a scatter or diffraction pattern} - G01N 21/51: inside a container, e.g. in an ampoule (G01N21/53 takes precedence) - G01N 21/645: {Specially adapted constructive features of fluorimeters} - G01N 21/83: Turbidimetric titration - G01J 2003/1217: {Indexed discrete filters or choppers} - G01N 2015/0222: {from dynamic light scattering, e.g. photon correlation spectroscopy} - G01N 2021/4792: {Polarisation of scatter light} - G01N 2021/6417: {Spectrofluorimetric devices} - G01N 2021/6471: {Special filters, filter wheel} - 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) - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) ## Abstract An instrument and a method for measuring the characteristics of particles in a sample. The instrument comprises a light source operable to provide a light beam and defining an illumination axis; a sample cell placed on the illumination axis; a scattered light detector positioned to receive scattered light along a detection path from a sample in the sample cell, the scattered light produced by the interaction of the light beam with the sample; and a filter changer positioned between the sample cell and the scattered light detector. The filter changer comprises at least one optical filter and an actuator. The actuator is operable to move each of the at least one optical filter between a first position in which the detection path does not pass through the optical filter, and a second position in which the detection path passes through the optical filter. ## Claims ### Claim 1 A particle characteristic measuring device, the device comprising: a light source that provides a light beam and that defines an illumination axis, a sample cell placed on the illumination axis, a scattered light detector positioned to receive scattered light along a detection path from a sample in the sample cell, the scattered light produced by interaction between the light beam and the sample, and a filter changer between the sample cell and the scattered light detector, the filter changer comprising: at least one optical filter comprising a first polarizing filter and a second polarizing filter, and an actuator that moves the at least one optical filter between: a first position in which the detection path does not pass through the optical filter; a second position in which the detection path passes through the first polarizing filter; and a third position in which the detection path passes through the second polarizing filter, wherein measurements taken through the first polarizing filter are combined with measurements taken through the second polarizing filter to determine a depolarized dynamic light scattering measurement. ### Claim 2 (depends on 1) The device of claim 1, comprising multiple optical filters and wherein the filter changer comprises a rotatable wheel, the wheel comprising multiple filter mounts that hold the multiple optical filters, and wherein the actuator rotates the wheel to move the filters between at least the first position and the second position. ### Claim 3 (depends on 1) The device of claim 1, wherein the at least one optical filter further comprises at least one of: a fluorescence filter, a band-stop filter, a band-pass filter, a high-pass filter and a low-pass filter. ### Claim 4 (depends on 1) The device of claim 1, comprising multiple optical filters and wherein the multiple optical filters comprise at least a first polarizing filter and a second polarizing filter. ### Claim 5 (depends on 4) The device of claim 4, wherein an axis of polarization of the first polarizing filter, when in the second position, is orthogonal to an axis of polarization of the second polarizing filter, when in the second position. ### Claim 6 (depends on 1) The device of claim 1, wherein the scattered light detector is positioned to receive back-scattered light, side-scattered light or forward-scattered light. ### Claim 7 (depends on 1) The device of claim 1, wherein the actuator comprises a motor. ### Claim 8 (depends on 1) The device of claim 1, wherein the device is configured to perform fluorescence correlation spectroscopy measurements. ### Claim 9 (depends on 1) The device of claim 1, comprising a controller, the controller operable to control the filter changer to move the at least one optical filter between the first, second, and third positions during characterization of a sample. ### Claim 10 (depends on 9) The device of claim 9, wherein the controller is operable, during characterization of a sample, to change which of the at least one filter is in the second position. ### Claim 11 (depends on 10) The device of claim 10, wherein the controller is operable, during characterization of a sample, to switch which of a first polarizing filter and a second polarizing filter are in the second position. ### Claim 12 (depends on 9) The device of claim 9, wherein the controller comprises a processor configured to control the operation of the filter changer. ### Claim 13 (depends on 1) The device of claim 1, comprising an auto-titrator and/or an auto-sampler. ### Claim 14 A particle characteristic measuring method, the method comprising: placing a sample in a sample cell, illuminating the sample with a light beam from a light source to produce scattered light by interaction between the light beam and the sample, moving at least one optical filter comprising a first polarizing filter and a second polarizing filter into a scattered light detection path between the sample and a detector using a filter changer, the filter changer comprising an actuator that moves the at least one optical filter between: a first position in which the detection path does not pass through the optical filter; a second position in which the detection path passes through the first polarizing filter; and a third position in which the detection path passes through the second polarizing filter, filtering the scattered light along the detection path with the first optical filter comprising a first polarizing filter and a second polarizing filter; and detecting the scattered light that has passed through the first optical filter with the detector, wherein measurements taken through the first polarizing filter are combined with measurements taken through the second polarizing filter to determine a depolarized dynamic light scattering measurement. ### Claim 15 (depends on 14) The method of claim 14, comprising: moving a second optical filter into the detection path, and detecting the scattered light that has passed through the second optical filter with a detector. ### Claim 16 (depends on 15) The method of claim 15, wherein moving the second optical filter into the detection path comprises moving the first optical filter out of the detection path. ### Claim 17 (depends on 15) The method of claim 15, wherein the filter changer comprises a rotatable wheel, and wherein moving the second optical filter comprises rotating the wheel. ### Claim 18 (depends on 15) The method of claim 15, wherein the second optical filter comprises at least one of a polarizing filter, a fluorescence filter, a band-stop filter, a band-pass filter, a high-pass filter and a low-pass filter.