Abstract: A particle characterisation instrument, comprising a light source, a sample cell, an optical element between the light source and sample cell and a detector. The optical element is configured to modify light from the light source to create a modified beam, the modified beam: a) interfering with itself to create an effective beam in the sample cell along an illumination axis and b) diverging in the far field to produce a dark region along the illumination axis that is substantially not illuminated at a distance from the sample cell. The detector is at the distance from the sample cell, and is configured to detect light scattered from the effective beam by a sample in the sample cell, the detector positioned to detect forward or back scattered light along a scattering axis that is at an angle of 0° to 10° from the illumination axis.

Abstract: A particle characterization apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; and a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample.

Abstract: A fluid characterization measuring instrument is disclosed that comprises a sample vessel for a bulk complex sample fluid having a capacity that is substantially larger than a domain size of the complex sample fluid and that is sufficiently large to cause bulk scattering effects to substantially exceed surface effects for the complex fluid sample, a coherent light source positioned to illuminate the bulk complex sample fluid in the sample vessel and a first fibre having a first end positioned to receive backscattered light from the sample after it has interacted with the sample. The first fibre can also be positioned close enough to an optical axis of the coherent light source and to the sample vessel to substantially decrease a contribution of multiply scattered light in the backscattered light.

Abstract: A particle characterization apparatus is disclosed comprising: a sample cell for holding a sample, a light source for producing a light beam for illuminating the sample in the sample cell, thereby producing scattered light by the interaction of the light beam with the sample; a focussing lens for focussing the light beam within the sample; and a detector for detecting the backscattered light along a detection optical path that intersects the focussed light beam within the sample. The intersection of the light beam and the detection optical path in the sample define a detection region. The apparatus comprises an optical arrangement for varying the volume of the detection region.

Abstract: An optical sample characterization method is disclosed comprising: holding a sample in a sample container proximate at least one two-dimensional detector array assembly, wherein the sample container has a first end and a second end; setting up a gradient between the first end of the sample container and the second end of the sample container; illuminating the sample between the first end of the sample container and the second end of the sample container; and detecting light received from the illuminated sample from the first end of the sample container to the second end of the sample container by the two-dimensional an-ay assembly.

Abstract: The invention relates to analyzing 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 of controlling collection of a sample of a liquid eluate output from a separation process. The method includes exposing the liquid eluate to light from a light source; detecting light from the light source scattered by suspended material in the eluate at a detector; and beginning and ending collection of the sample when a measure of the suspended material derived from the detected scattered light enters and leaves a predetermined range.

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

Abstract: This application discloses a method of using an apparatus comprising a processor to determine a diffusion coefficient (D) of a solute in a solution flowing in a capillary. The method includes obtaining a first signal comprising a plurality of measurements of solute concentration measured at a first measurement location corresponding with a first mean measurement time that is before a full dispersion condition is met; obtaining a second signal comprising a plurality of measurements of solute concentration measured at a second measurement location corresponding with a second mean measurement time that is after the first mean measurement time and before a full dispersion condition is met; calculating an actual front height ratio; a convection front height ratio; and a proportion of the solute that dispersed between the first mean measurement time and the second mean measurement time.

Abstract: An apparatus for particle characterisation, comprising: a sample cell for holding a sample; a light source configured to illuminate the sample with an illuminating beam and a plurality of light detectors, each light detector configured to receive scattered light resulting from the interaction between the illuminating beam and the sample along a respective detector path, wherein each respective detector path is at substantially the same angle to the illuminating beam.

Abstract: Disclosed in one general aspect is a particle interaction characterization instrument that comprises a flow cell for a liquid sample that includes suspended particles and a light source positioned to illuminate the suspended particles in the liquid sample fluid in the sample vessel. A first scattering detector is positioned to receive light from the light source that has been scattered by the particles suspended in sample fluid in the sample vessel at at least one predetermined scattering angle. An ultraviolet transmittance detector is positioned to receive a portion of the light from the source that passes through the suspended particles without being absorbed or scattered. Interaction analysis logic is responsive to both the scattering detector and the ultraviolet detector, and is operative to derive at least one interaction property for the suspended particles.

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.

Abstract: An optical sample characterization method is disclosed comprising: holding a sample in a sample container proximate at least one two-dimensional detector array assembly, wherein the sample container has a first end and a second end; setting up a gradient between the first end of the sample container and the second end of the sample container; illuminating the sample between the first end of the sample container and the second end of the sample container; and detecting light received from the illuminated sample from the first end of the sample container to the second end of the sample container by the two-dimensional array assembly.

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.

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.

Abstract: A particle characterization 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: Methods and apparatus for measuring particle characteristics are disclosed. In one aspect, an amount of light arising from interaction between light and a suspended sample is detected simultaneously with the acquisition of a photon count from a different direction. At least one measure of particle characteristics can then be derived based at least in part on timing between information from the steps of acquiring and detecting.