Abstract: A cuvette carrier comprising: a plurality of walls defining a holding volume for a cuvette; a first and second transmissive region included in the plurality of walls; and a first optical polariser arranged to polarise light passing through the first transmissive region.

Abstract: Viscometers and viscometry methods are disclosed. In one general aspect, a fluid is driven through capillary tubes with different inside volumes, and successive images of the fluid are acquired as it advances through the inside volume of the capillary tubes. A range of different viscosity values of the fluid are derived from the successive acquired images, and results of this step are reported in a manner that provides insight into non-Newtonian effects in the fluid. In another general aspect, a viscosity value is selected based on detected pressure levels.

Abstract: A rotary rheometer is disclosed that includes improved control logic. This logic can provide continuously sampled force control logic, compliance control logic, adaptive control logic, anti-windup logic, and/or inertial correction logic.

Abstract: The invention relates to methods and apparatus for detecting properties of heterogeneous samples, including detecting properties of particles or fluid droplets in industrial processes. Embodiments disclosed include a particle characterization method, comprising: providing a fluid containing suspended particles; causing at least a first subset of the suspended particles to flow past a first two-dimensional array detector (24); illuminating the first subset of suspended particles as they flow past the first two-dimensional array detector (24) in the fluid; acquiring a plurality of images of the first subset of particles as they flow past the first two-dimensional array detector (24) in the fluid; and automatically counting the particles in the images.

Abstract: Disclosed is a method of calibrating apparatus for optically characterizing samples of particles of small size. Also disclosed is a method of estimating the concentration of particles in a population of small size particles.

Abstract: Method of characterizing particles suspended in a fluid dispersant by light diffraction, comprising: obtaining measurement data from a detector element, the detector element being arranged to measure the intensity of scattered light; identifying a measurement contribution arising from light scattered by inhomogeneities in the dispersant; processing the measurement data to remove or separate the measurement contribution arising from light scattered by inhomogeneities in the dispersant; calculating a particle size distribution from the processed measurement. The detector element is one of a plurality of detector elements from which the measurement data is obtained. The detector elements are arranged to measure the intensity of scattered light at a plurality of scattering angles, the plurality of scattering angles distributed over a plurality of angles about an illumination axis.

Abstract: Apparatus (100) for measuring particle size distribution by light scattering comprises a blue LED (102) and a 633 nm helium neon laser (104). Light output from the LED and laser is separately passed or reflected by a dichroic element (116) onto a common path through a sample cell (122) containing a sample, the particle size distribution of which is to be measured. Light scattered from the sample cell is detected by one or more detectors (112B-H). Light transmitted by the sample cell is detected by detectors 112A, 112J. Output signals from one or more of the detectors are passed to a computation unit (114) which calculates particle size distribution. A small percentage of light from the blue LED is reflected by the dichroic element to a detector (110). Similarly, a small percentage of light from the laser is passed by the dichroic element to the detector. Output signals from the detector are fed back to control units (106, 108) to stabilize the output power of the LED and laser.

Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: The invention relates to methods and apparatus for detecting properties of suspended particles. Embodiments disclosed include an optical instrument (200) for detecting properties of a sample, comprising: a sample cell (103) for holding a sample of a particulate dispersion; a coherent light source (101) configured to illuminate the sample in the sample cell (103); a light intensity detector (104, 106) positioned to receive and measure an intensity of light from the coherent light source (101) elastically scattered by the sample in the sample cell (103); and a spectral light detector (212) positioned and configured to receive and measure a range of wavelengths of light from the coherent radiation source (101) inelastically scattered by the sample in the sample cell (103).

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.

Abstract: A particle characterisation apparatus is disclosed comprising: a first light source; a second light source, a sample cell; a first detector and a second detector. The first light source is operable to illuminate a first region of a sample comprising dispersed particles within the sample cell with a first light beam along a first light beam axis so as to produce scattered light by interactions of the first light beam with the sample. The first detector is configured to detect the scattered light. The second light source is operable to illuminate a second region of the sample with a second light beam along a second light beam axis. The second detector is an imaging detector, configured to image the particles along an imaging axis using the second light beam. The first light beam axis is at an angle of at least 5 degrees to the second light beam axis.

Abstract: A particle characterization apparatus having first and second body parts, a light source, a sample cell and a detector. The light source illuminates dispersed particles within the sample cell with a light beam along an axis to produce scattered light. The sample cell has first and second walls. The walls have internal surfaces arranged to be in contact with the sample and an opposite external surface. The light beam passes through the external surface of the first wall, through the internal surface of the first wall, through the sample, through the internal surface of the second wall, and through the external surface of the second wall. The light source is fixed to the first body part, which engages with the first wall. The detector is fixed to the second body part, which engages with the second wall. The first and second body parts are separable to enable access to the internal surfaces of the walls for cleaning.

Abstract: Disclosed is a method of calibrating apparatus for optically characterising samples of particles of small size. Also disclosed is a method of estimating the concentration of particles in a population of small size particles.

Abstract: A particle characterisation apparatus is disclosed comprising: a light source; a sample cell; a collecting lens and a detector. The light source is operable to illuminate a sample comprising dispersed particles within the sample cell with a light beam along a light beam axis. The light beam axis passes through a first wall of the sample cell, through the sample, and through a second wall of the sample cell, so as to produce scattered light by interactions with the sample. The detector is configured to detect light scattered from the sample. The second wall of the sample cell comprises a lens with a convex external surface through which the light beam axis passes. The collecting lens is arranged to collect and focus scattered light leaving the sample cell onto the detector, and comprises an aspheric surface.

Abstract: The invention relates to analysing and controlling collection of liquid eluate output from a separation process, in particular by use of a measure of suspended material in the eluate based on a light scattering detection method. Exemplary embodiments include a method (300) of controlling collection of a sample of a liquid eluate output from a separation process, the method comprising: exposing (306) the liquid eluate to light from a light source; detecting (307) light from the light source scattered by suspended material in the eluate at a detector; and beginning and ending collection (310) of the sample when a measure of the suspended material derived from the detected scattered light enters and leaves a predetermined range.

Abstract: The present invention provides a method of analyzing a sample comprising sub-micron particles, comprising determining first information about the size of particles and number of particles in the sample by nanoparticle tracking analysis; determining second information about average particle size of particles in the sample by dynamic light scattering; determining from the first information third information representing the theoretical effect of the detected particles on results obtainable by dynamic light scattering; and adjusting the second information using the third information to produce fourth information representing adjusted information on average particle size.

Abstract: A single photon counting apparatus comprising a SPAD and a controller. The controller is operable to vary the operating parameters of the SPAD during use in response to a count rate detected by the SPAD. The operating parameters comprising at least one of the voltage across the SPAD during an active period, the voltage across the SPAD during a quench period, the duration of the quench period and the temperature of the SPAD. Particle characterisation instruments comprising the apparatus are also disclosed.

Abstract: The disclosure relates to methods and apparatus for detecting properties of heterogeneous samples, including detecting properties of particles or fluid droplets in industrial processes. Embodiments disclosed include a particle characterization method, comprising: suspending particles in a fluid; causing the suspended particles to flow past a two-dimensional array detector; illuminating the suspended particles as they flow past the two-dimensional array detector in the fluid; acquiring a plurality of images of the particles as they flow past the two-dimensional array detector in the fluid; and applying a particle characterization function to results of steps of acquiring a plurality of images for at least some of the suspended particles.

Abstract: A rotary rheometer is disclosed that includes improved control logic. This logic can provide continuously sampled force control logic, compliance control logic, adaptive control logic, anti-windup logic, and/or inertial correction logic.

Abstract: A dilution apparatus suitable for use with particles suspended in a fluid is described. The apparatus comprises a first batch diluter and a second continuous diluter. The first diluter comprises a vessel having at least one inlet, and an outlet, the at least one inlet being arranged to receive diluent so as to mix said sample with said diluent. The second diluter comprises a sample input, a diluent inlet and an output, the diluent input being arranged such that diluent entering the second diluter experiences a pressure drop. The pressure drop is sufficient to entrain at least a portion of diluted sample from the first diluter through the sample input. The outlet of the first diluter is arranged to be in communication with the input of the second diluter such that a sample that has been pre-diluted in the first diluter is arranged to be further diluted in the second diluter.