An illuminator/collector assembly can deliver incident light to a sample and collect return light returning from the sample. A sensor can measure ray intensities as a function of ray position and ray angle for the collected return light. A ray selector can select a first subset of rays from the collected return light at the sensor that meet a first selection criterion. In some examples, the ray selector can aggregate ray intensities into bins, each bin corresponding to rays in the collected return light that traverse within the sample an estimated optical path length within a respective range of optical path lengths. A characterizer can determine a physical property of the sample, such as absorptivity, based on the ray intensities, ray positions, and ray angles for the first subset of rays. Accounting for variations in optical path length traversed within the sample can improve accuracy.

Provided are an optical system for measuring optical characteristics and a device for measuring optical characteristics capable of acquiring a two-dimensional image close to visual observation in addition to measurement of optical characteristics of a measurement target. The optical system for measuring optical characteristics includes a first optical system (11) that captures an infinite conjugate image and a second optical system (12) that captures a conjugate image of a measurement target. The first optical system (11) and the second optical system (12) sharing a first lens group (G1) are arranged on two optical axes separated by an optical element (5) that deflects an optical axis, respectively, and are configured as one measuring optical system. Furthermore, an aperture stop of the second optical system (12) is arranged in the vicinity of an intermediate image When a distance in an optical axis direction from an image side paraxial focal point of the first lens group (G1) to the aperture stop is represented by Δp, and a focal distance of the first lens group is represented by f1, Δp/f1 satisfies −1.0<Δp/f1<3.0.

An optical cell for performing light spectroscopy (including absorbance, fluorescence and scattering measurements) on a liquid sample in microfluidic devices is disclosed. The optical cell comprises an inlaid sheet having an opaque material inlaid in a clear material, and a sensing channel that crosses the clear material and the opaque material provides a fluidic path for the liquid sample and an optical path for probe light. Integral optical windows crossing a clear-opaque material interface permit light coupling into and out of the sensing channel, and thus light transmission through the sensing channel is almost entirely isolated from background light interference. A microfluidic chip comprising one or more optical cells is also disclosed. The optical cells may have different lengths of sensing channels, and may be optically and fluidly coupled. A method of manufacturing an optical cell in a microfluidic chip is also disclosed.

The present relates to a measurement device (1) for the detection and/or measurement of particles in a fluid, the measurement device comprising a fluid source (11) for producing a flow of fluid (111) along a fluid flow path, a first laser source (12) positioned for emitting a first laser beam (120) of laser light in a measurement volume of the fluid flow path for light scattering; a scattered light detecting means (13) for detecting a presence of a particle in the fluid flow path through detection and measurement of laser beam light scattered on different angles by said particle, wherein it further comprises a second laser source (14) positioned for emitting a second laser beam (140) of laser light in said measurement volume of the fluid flow path for Raman and fluorescence excitation; a Raman and fluorescence detecting means (15) for detecting a Raman scattering signal emitted by the fluid and a Fluorescence signal emitted by said particle upon excitation by said second laser beam (140).

A method of determining particle size distribution from multi-angle dynamic light scattering data, comprising: obtaining a series of measured correlation functions g(θ.sub.i) at scattering angles θ.sub.i; and solving an equation comprising $\left[\begin{array}{c}g\left({\theta }_1\right)\\ \mathrm{.Math.}\\ g\left({\theta }_n\right)\end{array}\right]=\left[\begin{array}{c}{\alpha }_{1}K\left({\theta }_1\right)\\ \mathrm{.Math.}\\ {\alpha }_{n}K\left({\theta }_n\right)\end{array}\right]x,$
wherein: K(θ.sub.i) is the instrument scattering matrix computed for angle i, x is the particle size distribu

The present invention relates to a method for determining the composition of a multi-layer system showing a predetermined colour flip-flop effect, wherein the multi-layer system comprises from bottom to top a) a substrate, b) at least one first colour layer containing a colourant, which is arranged on the substrate a), c) on the at least one first colour layer an effect layer containing at least one platelet-shaped effect pigment, and d) on the effect layer c) at least one second colour layer containing a colourant, wherein each of the at least one first colour layer and of the at least one second colour layer contains a colourant being no platelet-shaped effect pigment, wherein the method comprises the following steps: i) specifying a first target value for the colour shade and/or colour brightness of the top side of the multi-layer system seen at a first observation angle, ii) specifying a second target value for the colour shade and/or colour brightness of the top side of the multi-layer system seen at a second observation angle, wherein the second observation angle is different from the first observation angle, and wherein the second target value is different from the first target value, iii) specifying a colourant system comprising at least one colourant and further comprising one effect pigment layer recipe being suitable for forming the effect layer c), iv) providing at least one empirical model of the relationship between the colour shades and/or colour brightness at least two different observation angles comprising at least the first observation angle and the second observation angle specified in step ii) of the top side of a first number of multi-layer systems, at least 90% of which comprising at least one first colour layer b) having at least one colourant as specified in step iii), at least one second colour layer d) having at least one colourant as specified in step iii) and an effect layer c) made of the effect pigment layer recipe specified in step iii), and v) determining—making use of the at least one empirical model provided in step iv)—the composition of a multi-layer system (10) having within a predetermined tolerance the first target value specified in step i) and the second target value specified in step ii), or, if none is found, specifying a new tolerance for the first target value specified in step i) and/or the second target value specified in step ii), or specifying in steps i) and ii) a new first target value and/or new the second target value, or repeating the method by specifying in step iii) a different colourant system, which preferably covers more different colourants than the colourant system used before, wherei

One or more homogenizing elements are employed in a flow through, multi-detector optical measurement system. The homogenizing elements correct for problems common to multi-detector flow-through systems such as peak tailing and non-uniform sample profile within the measurement cell. The homogenizing elements include coiled inlet tubing, a flow distributor near the inlet of the cell, and a flow distributor at the outlet of the cell. This homogenization of the sample mimics plug flow within the measurement cell and enables each detector to view the same sample composition in each individual corresponding viewed sample volume. This system is particularly beneficial when performing multiangle light scattering (MALS) measurements of narrow chromatographic peaks such as those produced by ultra-high pressure liquid chromatography (UHPLC).

Systems and methods for smoke detection which utilizes two generally identical light sources and single light detector to compare the ratio of forward and backward scattering smoke particles present in a detection area.

The present disclosure relates to determining, in a fluid sample, particle(s) having a predetermined size or range of sizes within a detection zone using a particle detector, and includes: providing first and second lights to illuminate the sample within the detection zone; the first light being: a first polarisation at a first wavelength; a single wavelength having a first polarisation; or an unpolarised first wavelength; the second light being: a second polarisation at a second wavelength; the single wavelength having a second polarisation; or an unpolarised second wavelength; first sensor means obtaining a first response signal responsive to the first light impinging a particle; a second sensor means obtaining a second response signal responsive to the second light impinging a particle; determining a light scattering intensity at each light and a quotient thereof; and determining size of particle(s) by correlating light intensity values with values in a look-up table.

Described herein is a computer-implemented process which includes at least the following steps: receiving at least one image or a plurality of images, implementing an image analysis for each of the images obtained, using at least one processor, identifying at least one sparkle point within a respective image, implementing a features analysis of the at least one identified sparkle point in the respective image in respect of at least one predefined size feature, determining at least one value for the at least one predefined size feature for the at least one sparkle point, calculating a size distribution for the respective image based on the determined value for the at least one predefined size feature, and providing a formulation for a coating which is identical or at least similar in appearance to the target coating.