Abstract: Black coatings on optical substrates, compositions for producing such coatings and the use of the compositions for edge-blackening and stray light control. The present coatings comprise a film formed by a cured polymer mixed with nanoparticles and black pigment, wherein the film has a refractive index of more than 1.6. The present compositions comprise 5 to 100 parts by weight of a curable polymer; 5 to 100 parts by weight of nanoparticles; and 0.1 to 20 parts by weight of black pigment, and the nanoparticles and black pigment are mixed with the curable polymer. The present compositions exhibit RI values which match that of high-RI glass substrates while providing efficient edge-blackening properties.

Abstract: The present disclosure relates to light arrangement for an optical device for measurement of an index of refraction, having a light source, a fiber bundle arrangement for transmitting light from the light source, a diffusing member, and imaging optics for transmitting the light to a measuring window. In order to provide for an arrangement which is durable and accurate even when used for measuring hot specimens where the light source is positioned far from the measuring window, the fiber bundle arrangement includes a novel combination of a first fiber bundle and a second fiber bundle.

Abstract: The present disclosure relates to light arrangement for an optical device for measurement of an index of refraction, having a light source, a fiber bundle arrangement for transmitting light from the light source, a diffusing member, and imaging optics for transmitting the light to a measuring window. In order to provide for an arrangement which is durable and accurate even when used for measuring hot specimens where the light source is positioned far from the measuring window, the fiber bundle arrangement includes a novel combination of a first fiber bundle and a second fiber bundle.

Abstract: An optical measuring device including a measuring head, an inner shell including a light transmitter and a light receiver, an outer shell including a measurement orifice in one end and a fastening flange part in another end, the inner shell is arranged at least partially in the outer shell, the measuring head is arranged in the outer shell and attached to the measurement orifice from its first end and to an end of the inner shell from its second end, a gasket is arranged between the measuring head and the measurement orifice, and inside the outer shell is arranged a fluid flow path extending from the gasket towards the fastening flange part, wherein to the outer shell is formed a leak detection port having one end opening into the fluid flow path and another end opening into a side surface of the outer wall in the fastening flange part wherein a fastening flange protrudes between the opening into the side surface and the measurement orifice.

Abstract: A method and arrangement are disclosed for measuring a flow rate of optically non-homogeneous material in a process pipe. The non-homogeneous material can be illuminated through a window. Images are taken with a camera, through a window, of illuminated non-homogeneous material. Correlation between temporally successive images determines travel performed by the non-homogeneous material in the process pipe between capture of temporally successive images. Velocity of the non-homogeneous material is determined by the time difference between the successive images and the travel.

Abstract: A method and arrangement are disclosed for measuring a flow rate of optically non-homogeneous material in a process pipe. The non-homogeneous material can be illuminated through a window. Images are taken with a camera, through a window, of illuminated non-homogeneous material. Correlation between temporally successive images determines travel performed by the non-homogeneous material in the process pipe between capture of temporally successive images. Velocity of the non-homogeneous material is determined by the time difference between the successive images and the travel.

Abstract: In a method for illuminating particles contained in a medium for optical analysis, and an optical particle analyzer, the medium is subjected to a light beam through a window which illuminates the particles to form an image of the particles. The window comprises a trapezoidal prism, a longer side surface of the parallel side surfaces of which forms a surface facing the medium. In the vicinity of the prism, the light beam is directed by a mirror surface and a cylindrical lens, which converts a shift of the light source to a change in the light beam angle.

Abstract: The invention relates to a method for illuminating particles contained in a medium for optical analysis, and an optical particle analyser. The medium is in contact with a window and subjected to a light beam that comes from a light source, through the window, and illuminates the particles to form an image of the particles; the window that is used being a trapezoidal prism a longer side surface of the parallel side surfaces of which forms a surface facing the medium.