A device for scattered light measurement of particles in a gas, comprising a light source, a beam splitter which splits a light beam emitted by the light source into a measuring beam and a reference beam, a light receiving device arranged at a distance from the beam splitter, which comprises at least one lens arranged in the reference beam with an optical axis aligned at an acute angle to the measuring beam, a first light receiver on the side of the lens facing away from the beam splitter, for receiving the scattered light imaged by the latter from a measurement volume in a gas-bearing region between the beam splitter and the lens, and a second light receiver on the side of the lens facing away from the beam splitter for receiving the reference beam imaged by the latter.

The present disclosure describes a differential refractometer for gradient chromatography. In an exemplary embodiment, the differential refractometer includes a solvent delay volume, an eluent flow meter coupled to an eluent inlet of a sample cell, a solvent flow regulator coupled to an outlet of the solvent delay volume and coupled to a solvent inlet of a reference cell, an instrument controller configured to receive the eluent flow rate from the eluent flow meter, configured to receive the solvent flow rate from the solvent flow regulator, configured to receive a flow rate ratio from a flow rate ratio data source, wherein the flow rate ratio indicates a ratio of the eluent flow rate to the solvent flow rate, and an optical bench configured to measure a difference between a refractive index of the eluent present in the sample cell and a refractive index of the solvent present in the reference cell.

The present disclosure describes a differential refractometer for gradient chromatography. In an exemplary embodiment, the differential refractometer includes a solvent delay volume, an eluent flow meter coupled to an eluent inlet of a sample cell, a solvent flow regulator coupled to an outlet of the solvent delay volume and coupled to a solvent inlet of a reference cell, an instrument controller configured to receive the eluent flow rate from the eluent flow meter, configured to receive the solvent flow rate from the solvent flow regulator, configured to receive a flow rate ratio from a flow rate ratio data source, wherein the flow rate ratio indicates a ratio of the eluent flow rate to the solvent flow rate, and an optical bench configured to measure a difference between a refractive index of the eluent present in the sample cell and a refractive index of the solvent present in the reference cell.

A method for measuring concentrations of blood cell components is provided. The method comprises: obtaining a blood sample from a subject, the blood sample comprising at least one of red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs); mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity; passing the sample mixture through a flow cell; emitting light towards the flow cell; measuring at least one of an amount of light absorbed by the RBCs to obtain an RBC absorption value, an amount of light scattered by WBCs to obtain a WBC scatter value, and an amount of light scattered by PLTs to obtain a PLT scatter value; and determining a concentration of at least one of the RBCs, WBCs, and PLTs present in the sample mixture.

A method for measuring concentrations of blood cell components is provided. The method comprises: obtaining a blood sample from a subject, the blood sample comprising at least one of red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs); mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity; passing the sample mixture through a flow cell; emitting light towards the flow cell; measuring at least one of an amount of light absorbed by the RBCs to obtain an RBC absorption value, an amount of light scattered by WBCs to obtain a WBC scatter value, and an amount of light scattered by PLTs to obtain a PLT scatter value; and determining a concentration of at least one of the RBCs, WBCs, and PLTs present in the sample mixture.

Any one or both of an optical system with a structured lighting pattern and a structured detecting system having a plurality of regions with different optical characteristics are used. In addition, optical signals from an object to be observed through one or a small number of pixel detectors are detected while changing relative positions between the object to be observed and any one of the optical system and the detecting system, time series signal information of the optical signals are obtained, and an image associated with an object to be observed from the time series signal information is reconstructed.

Any one or both of an optical system with a structured lighting pattern and a structured detecting system having a plurality of regions with different optical characteristics are used. In addition, optical signals from an object to be observed through one or a small number of pixel detectors are detected while changing relative positions between the object to be observed and any one of the optical system and the detecting system, time series signal information of the optical signals are obtained, and an image associated with an object to be observed from the time series signal information is reconstructed.

A smoke detector of the type that depends on the scattering of light by smoke particles comprising a chamber (301) configured to receive smoke particles from an environment in which the smoke detector is required to detect smoke, a source of light (202) configured to project light therefrom such that light that is received by the chamber is scattered by the smoke particles, an optical element (207) configured to receive light as has been scattered by the smoke particles, and, a photodetector (208) configured to detect at least some of the received scattered light, the smoke detector characterized in that upon receiving the scattered light, the optical element (207) is configured to selectively differentiate between required scattered light that is derived from a subset of predefined directions with respect to the angle of incidence upon the optical element and scattered light that is derived from other directions in order to thereby filter out the light that is not required and thereby redirect the required scattered light onto the photodetector (208).

A smoke detector of the type that depends on the scattering of light by smoke particles comprising a chamber (301) configured to receive smoke particles from an environment in which the smoke detector is required to detect smoke, a source of light (202) configured to project light therefrom such that light that is received by the chamber is scattered by the smoke particles, an optical element (207) configured to receive light as has been scattered by the smoke particles, and, a photodetector (208) configured to detect at least some of the received scattered light, the smoke detector characterized in that upon receiving the scattered light, the optical element (207) is configured to selectively differentiate between required scattered light that is derived from a subset of predefined directions with respect to the angle of incidence upon the optical element and scattered light that is derived from other directions in order to thereby filter out the light that is not required and thereby redirect the required scattered light onto the photodetector (208).

A device for measuring the turbidity of cerebrospinal fluid includes, a source of a light signal comprising having one or more wavelength(s), such that at least part of the emitted light signal passes through the cerebrospinal fluid; a flow element including an inlet and an outlet, the flow element being suitable for allowing cerebrospinal fluid to flow between the inlet and the outlet; an opaque element, arranged to absorb at least part of the emitted light signal after it has passed through the cerebrospinal fluid, and to allow another part of the emitted light signal to be reflected after it has passed through the cerebrospinal fluid; and an optical detector configured to detect the light signal after it has passed through the cerebrospinal fluid.