Abstract: An apparatus and method are disclosed for obtaining and analyzing light scattering data to determine the size distribution of a group of dispersed particles that scattered the light. The apparatus and method use a two-dimensional array of photosensitive pixels such as a charge-coupled device (CCD) or an array of solid-state photodiodes. The analyzer illuminates the particles with a dose of light in a collimated beam from a light source so as to scatter light of the beam, and at least a portion of the light interacting with the particles is detected with the photosensitive pixel array. The pixels are functionally equivalent and the analyzer dynamically configures and re-configures at least a portion of the pixels into a variable number of data collection areas which correspond to a selected set of scattering angles. The analyzer also determines whether and, from the pixel output data, where an unscattered center of the incident light beam intersects the pixel array.

Abstract: An apparatus and method are disclosed for obtaining and analyzing light scattering data to determine the size distribution of a group of dispersed particles that scattered the light. The apparatus and method use a two-dimensional array of photosensitive pixels such as a charge-coupled device (CCD) or an array of solid-state photodiodes. The analyzer illuminates the particles with a dose of light in a collimated beam from a light source so as to scatter light of the beam, and at least a portion of the light interacting with the particles is detected with the photosensitive pixel array. The pixels are functionally equivalent and the analyzer dynamically configures and re-configures at least a portion of the pixels into a variable number of data collection areas which correspond to a selected set of scattering angles. The analyzer also determines whether and, from the pixel output data, where an unscattered center of the incident light beam intersects the pixel array.

Abstract: An x-ray sedimentation particle size analyzer in which data is taken only at particular positions along the sedimentation cell, and each such position is individually calibrated. Presentation of the data in the form of a particle size distribution curve can be accomplished very accurately using interpolation techniques. The sedimentation cell design is free of the effects of undesirable density gradients, capable of detecting and removing bubbles, capable of attaining a highly uniform dispersion of sample prior to sedimentation, and including a safety interlock device for blocking x-ray projection when the cell is being accessed.

Abstract: Improved method and apparatus for injecting a predetermined amount of a sample liquid into a high pressure stream of carrier liquid for introduction into a liquid chromatography column, wherein the flow of high pressure carrier liquid in the column is maintained at a substantially constant pressure and rate of flow, including periodically accumulating a precise amount of sample liquid in a primary flow path of carrier liquid to the column while automatically diverting all of the carrier liquid into a secondary flow path to the column in response to a small increase in carrier liquid pressure upstream of the sample accumulation point. Also disclosed is a three position, rotary sample injection valve having improved sealing means for introducing a sample liquid into a high pressure carrier liquid.

Abstract: Sample introduction apparatus useful in liquid chromatography and including a valve body having at least one fluid passage of precisely defined volume to receive a sample material and having another fluid passage delivering carrier liquid to a liquid chromatograph. The valve body can be manipulated to place the precisely defined volume in the chromatograph fluid circuit, so that the sample contained within the volume is positively displaced into the chromatograph.

Abstract: Apparatus used in the field of liquid chromatography. There is disclosed pump apparatus for continuously delivering a flow of carrier liquid either at a constant rate of flow or at a constant pressure. The pump apparatus includes a pair of differential-piston pressure intensifiers which are sequentially operated so that the high-pressure sides of the pressure intensifiers sequentially supply carrier liquid to the chromatograph column. Each pressure intensifier is sequentially operated by a constant-rate of flow application of hydraulic liquid, with essentially pulseless operating transition between pressure intensifiers occurring during constant-pressure application of hydraulic liquid to both of the pressure intensifiers at a pressure measured during previous constant-volume hydraulic operation. An embodiment of the pump apparatus pumps plural carrier liquids in desired fixed or variable proportions.