Abstract: Apparatus (200) for measuring the particle-size distribution of a sample by light-scattering comprises a focusing optic (202) for producing a converging beam (203) generally along a propagation axis z. The apparatus comprises a mounting system which allows a dry sample cell (208A) and a wet sample cell (208B) 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 (212, 214) 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.

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: 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: 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 stabilise the output power of the LED and laser.

Abstract: Apparatus (200) for measuring the particle-size distribution of a sample by light-scattering comprises a focusing optic (202) for producing a converging beam (203) generally along a propagation axis z. The apparatus comprises a mounting system which allows a dry sample cell (208A) and a wet sample cell (208B) 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 (212, 214) 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.

Abstract: An apparatus for providing a light beam for use in a diffraction instrument (1) includes a device (10; 17; 28) for generating a light beam; and means (12, 21; 24) for shaping the light beam generated by the device (10; 17; 28), dimensioned, in use, to determine the beam shape, and including: an aperture (21; 25) and means (13; 24) for rejecting spatial frequency components above a certain range in the light beam. The apparatus further includes a spatial low-pass filter (14; 15; 26; 27) arranged to filter a beam provided by the beam shaping means.

Abstract: An apparatus for providing a light beam for use in a diffraction instrument (1) includes a device (10; 17; 28) for generating a light beam; and means (12, 21; 24) for shaping the light beam generated by the device (10; 17; 28), dimensioned, in use, to determine the beam shape, and including: an aperture (21; 25) and means (13; 24) for rejecting spatial frequency components above a certain range in the light beam. The apparatus further includes a spatial low-pass filter (14; 15; 26; 27) arranged to filter a beam provided by the beam shaping means.