A new liquid flow cell assembly for light scattering measurements is disclosed which utilized a floating manifold system. The assembly operates with minimal stacked tolerances by aligning the cell to the windows within a manifold and independently aligning the cell to the read head directly. This configuration enables the ability to replace the flow cell or the flow cell/manifold assembly within a light scattering instrument without the need to realign the flow through elements with the light scattering illumination source while still maintaining reproducible, quality data. Some embodiments employ wide bore cells which enable the measurement of process analytic technology (PAT) including online monitoring of reactions.

A method measuring the phase transition characteristics of a macromolecule, the method comprising: generating a stream of micro-droplets comprising at least one constituent, of which one constituent comprises the macromolecule, varying the conditions in the micro-droplets; and measuring the relative concentrations of the constituents of, and the phases of the macromolecule present in, the micro-droplets.

Systems and methods are provided for sample processing. A device may be provided, capable of receiving the sample, and performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing multiple assays. The device may comprise one or more modules that may be capable of performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing the steps using a small volume of sample.

The invention relates to methods and apparatus for determining properties of a surface. Embodiments disclosed include an apparatus for measuring a surface charge of a sample, comprising: a sample holder having an opposed pair of electrodes and configured to hold a sample in position in a measurement volume between the electrodes such that a planar surface of the sample is aligned orthogonal to the electrode surfaces; a measurement chamber for containing a measurement liquid and having an open end configured to receive the sample holder to position the electrodes in a preset orientation; a laser light source positioned and configured to direct a laser beam through the measurement chamber between the electrodes and parallel to the planar surface of the sample when the sample holder is received in the measurement chamber; and a detector positioned and configured to detect scattered light from the measurement volume, wherein the apparatus is configured to allow for detection of the scattered light by the detector over a range of distances from the surface of the sample.

A particle counter for chemical solution in this disclosure uses a flow cell through which a chemical solution including particles flows, a laser light, and a light-receiving element array. Scattered light from the particles passing through a detection region on an optical path of the laser light in the flow cell is condensed to the light-receiving element array. The laser light in the center of the detection region has an energy density of 3×10.sup.8 mW/cm.sup.2 or more. Each of plural light-receiving elements (a) is larger in length and width than a spot diameter of the scattered light, and (b) receives the scattered light from a region with a size of 760 μm.sup.2 or less included in the detection region. The signal processing unit counts the particles passing through the detection region by use of a threshold corresponding to the smallest measurable particle size of 0.03 μm.

A nephelometer that measures turbidity of low volume suspensions using measurements of light transmitted through and/or scattered by the sample. The sample suspension is placed in a tiered cuvette adapted to facilitate measuring the turbidity of low volume samples. The lower portion of the cuvette has smaller dimensions, in horizontal cross section, than the top portion. Both lower and upper portions have angled surfaces. The lower, smaller portion of the cuvette is interrogated by the nephelometer.

Turbidity measurement systems and methods of using the same are described. A turbidity measurement system comprise a vessel configured to hold a wellbore fluid, wherein a permeable obstruction to flow is positioned in the vessel; a light source positioned to direct light at the vessel; a light detector positioned to measure light intensity of light emitted by the light source and passing through the vessel; and a backscatter detector positioned to measure the light intensity of reflected light emitted from the light source.

A measurement apparatus according to the present disclosure is a measurement apparatus capable of measuring particles in a fluid and comprises: a flow path device including a first flow path with translucency through which a first fluid including the particles passes and a second flow path with translucency through which a second fluid which does not include the particles passes; an optical sensor facing the flow path device, irradiating each of the first flow path and the second flow path with light, and receiving light passing through each of the first flow path and the second flow path; and a controller measuring the particles by comparing an intensity of light passing through the first flow path and an intensity of light passing through the second flow path, each of which is obtained by the optical sensor.

A test unit having a light source (e.g., a laser) for illuminating an aerosol sample directed into a test chamber and a removable insert for the test unit. The test unit includes at least one detector for detecting the effect of the aerosol sample on light, i.e., the detector detects at least one property of light after the light has illuminated the aerosol sample. The removable insert may take a number of different forms. For example, the removable insert can form at least a portion of an unsealed or sealed test chamber when installed in an operating position. Further, the removable insert may include a removable support and at least one film or collection substance connected or applied to the removable support. The at least one film could be a filter or a non-filter. The filter could be a polarization filter (i.e., horizontal or vertical) or a fluorescence filter.

A nephelometric turbidimeter with a cylindrical turbidimeter vial. The cylindrical turbidimeter vial includes a transparent vial body and a circular optical shielding configured to optically block an inside from an outside of the turbidimeter vial. The vial body comprises a transparent and flat bottom inlet window, and a transparent vial cylinder body. The vial cylinder body comprises a circular outlet window. The optical shielding is arranged axially above the outlet window of the vial cylinder body, over a part of an axial length of the vial cylinder body, and axially adjacent to a non-shielded part of the vial cylinder body which serves as the outlet window.