A method for detecting and counting particles suspended in fluids, such as bacteria suspended in urine, utilizing dynamic features of the suspended particles and employing light scattering measurements. The disclosed method is suitable for determining the susceptibility of bacteria to antibiotics. A cuvette for detecting bacteria in fluids, which is especially suited for the light scattering measurements, is provided.

A water analysis device having a light source and a light detector for detecting an optical parameter of a water sample in a transparent measuring cell is disclosed. A ventilation circuit for ventilating a cell chamber is provided, wherein there is a differential pressure of at least 2.0 mbar between the cell chamber and the atmosphere when a ventilation pump is operated. The device housing forms the cell chamber which is fluidically sealed by a cover assembly. The cover assembly and the device housing have a mechanism that mimics the sealing action of a turn-lock fastener, such that the cover assembly can be secured to and/or released from the device housing by means of a rotational movement. The cover assembly and the device housing form an annular ring seal which is coaxial with the rotational movement and which is formed by an elastic sealing body having a circular sealing lip and a correspondingly circular shoulder seat on which the sealing lip is pressed due to the atmospheric differential pressure. Other aspects are disclosed and claimed.

The present disclosure describes a flow cell, a read head, and a skid attachment for measuring real-time molecular weight for downstream process control. In an embodiment, the flow cell comprises a hollow cylindrical tube, an inlet flange connected to an inlet of the tube, and an outlet flange connected to an outlet of the tube. In an embodiment, the read head comprises at least one push rod, at least two line contacts, where the at least one push rod is configured to push an outer side wall of a flow cell against the at least two line contacts. In an embodiment, the skid attachment comprises a plurality of arms connected to an enclosure configured to house at least a multi-angle light scattering instrument comprising a read head.

[Problems] Objects include providing a cover film for testing which can be well fixed to a substrate having a groove and in which a pressure sensitive adhesive does not invade into the groove, providing a testing member comprising the cover film for testing, and providing a method of manufacturing the cover film for testing. [Solution] The cover film for testing (1, 2) comprises a base material (10) and a pressure sensitive adhesive layer (20) laminated on one surface side of the base material (10). The cover film for testing (1, 2) has a region in which the pressure sensitive adhesive layer (20) does not exist in the plan view.

An apparatus and method to obtain electrophoretic mobility information from a dilute colloidal dispersion using electrophoretic light scattering (ELS) is disclosed. Both laser Doppler electrophoresis and phase analysis light scattering data analysis methods may be applied to a scattered light signal simultaneously. Unlike previous ELS apparatuses and methods, the disclosed apparatus and method can measure electrophoretic mobility distributions in high ionic strength media. It can detect the presence of electrochemical phenomena such as electrode polarization and electrolysis, and apply corrections to the measured electrophoretic mobility values thus providing electrophoretic mobility information about samples with greater accuracy, precision, and reliability than prior ELS implementations. Improvements to the optical configuration of the apparatus are also disclosed that increase the robustness of the apparatus. Many of the aspects of the disclosure may be applied to the measurement of electrophoretic mobilities of particles in low polarity media and also particles with low surface charge in polar or non-polar media with greater accuracy, precision, and reliability than prior ELS implementations.

The present invention is a cuvette assembly for use in optically measuring at least one characteristic of particles within a plurality of liquid samples. The cuvette assembly comprises a main body having internal walls and external walls, and a plurality of cuvettes within the main body at least partially being defined by the internal walls. Each of the plurality of cuvettes has a liquid-input chamber for receiving a respective one of the plurality of liquid samples, a filter, and an optical chamber for receiving a respective filtered liquid sample caused by passing the respective one of the plurality of liquid samples through the filter. Each of the optical chambers includes an entry window for allowing transmission of an input light beam through the filtered liquid sample and an exit window for transmitting a forward scatter signal caused by the particles within the filtered liquid sample.

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. The instrument can further comprise a first photon-counting detector positioned to receive the backscattered light from a second end of the fibre, correlation logic responsive to the first photon-counting detector and single-scattering fluid property analysis logic responsive to the correlation logic and operative to derive at least one fluid property for the sample fluid.

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 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.

An automatic analysis apparatus is capable of replacing circulated water in a reaction vessel and continuously cooling a light source lamp without stopping an operation for measuring a specimen. In an operation state, a drain electromagnetic valve 49 is opened to drain reaction vessel water outside and when the water level reaches a measurement limit water level, the drain electromagnetic valve 49 is closed. The reaction vessel water is supplied by starting a water supply pump, opening a water supply electromagnetic valve and when the water level has reached a full water level, the water supply electromagnetic valve is closed, and the water supply pump is stopped. In a state other than the operation state, the reaction vessel water is drained outside. When the water level has reached a circulation limit water level, the drain electromagnetic valve is closed.