Malvern Instruments Limited

Malvern Panalytical Inc.

David Michael Spriggs

David Stringfellow

Duncan Edward Stephenson

Nigel Lightfoot

Lewis Jones

Clive Catterall

Duncan Stephenson

A particle characterization 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.

Apparatus for characterizing particles and method for use in characterizing particles

Apparatus () for measuring the particle-size distribution of a sample by light-scattering comprises a focusing optic () for producing a converging beam () generally along a propagation axis z. The apparatus comprises a mounting system which allows a dry sample cell (A) and a wet sample cell (B) to be mounted in the converging beam at different times and in respective planes which are mutually inclined so that in use of the apparatus respective positions () at which transmitted light is focused for the two cells have a difference in displacement from the z axis that is less than for the case where the respective planes are substantially parallel. This allows use of a cheaper and less complex translation stage within the apparatus for mounting an optical detector for locating the two focus positions.

Apparatus and method for measuring particle size distribution by light scattering

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.

Improvements relating to particle characterisation

Relating to particle characterisation

Apparatus () for measuring particle size distribution by light scattering comprises a blue LED () and a 633 nm helium neon laser (). Light output from the LED and laser is separately passed or reflected by a dichroic element () onto a common path through a sample cell () 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 (B-H). Light transmitted by the sample cell is detected by detectorsA,J. Output signals from one or more of the detectors are passed to a computation unit () which calculates particle size distribution. A small percentage of light from the blue LED is reflected by the dichroic element to a detector (). 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 () to stabilize the output power of the LED and laser.

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.

Particle characterization

An apparatus for providing a light beam for use in a diffraction instrument () includes a device () for generating a light beam; and means () for shaping the light beam generated by the device (), dimensioned, in use, to determine the beam shape, and including: an aperture () and means () for rejecting spatial frequency components above a certain range in the light beam. The apparatus further includes a spatial low-pass filter () arranged to filter a beam provided by the beam shaping means.

Apparatus and method of producing a light beam for an optical measurement instrument

In one general aspect, a particle characterization instrument is disclosed that includes a first spatially coherent light source with a beam output aligned with an optical axis. A focusing optic is positioned along the optical axis after the coherent light source, and a sample cell is positioned along the optical axis after the focusing optic. The instrument also includes a diverging optic positioned along the optical axis after the sample cell, and a detector positioned outside of the optical axis to receive scattered light within a first range of scattering angles from the diverging optic. In another general aspect, an instrument can direct at least a portion of a first beam and at least a portion of a second beam along a same optical axis and a can receive scattered light from the sample cell resulting from interaction between the sample and either the first beam or the second beam.

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Malvern, United Kingdom

David Michael Spriggs