Abstract: An exemplary arrangement includes a prism-shaped measuring window, which has a measuring surface adapted to contact a substance being measured. A first surface is adapted to direct light originating from a light source to the measuring surface through the measuring window. A second surface is adapted to direct totally reflected light from an interface between the measuring surface in contact with the substance being measured and a substance being measured outside of the measuring window. A first lens arrangement is adapted to focus the light from the light source on the first surface. A second lens arrangement is adapted to focus the totally reflected light passing through the second surface to a device used for analysis. A lens in each of the first and second lens arrangements closest to the measuring window is integrated into the measuring window and establishes optical refractive power in the first and second surfaces.

Abstract: A method and an arrangement are disclosed in connection with a measurement arrangement of optical parameters of a separate sample taken from a process liquid, in which method a sample is taken from the process liquid. The sample can be arranged into a sample vessel provided with at least one measurement window, and optical parameters of the sample in the sample vessel are measured through the measurement window. In the sample in the sample vessel, a flow is produced which can be used to mitigate (e.g., prevent) the measurement window surface in contact with the sample from getting dirty. A back-and-forth flow can be produced in the sample residing in the sample vessel by means of pressure variation focused on the sample, and the back-and-forth flow can be focused on the surface of the optical measurement window.

Abstract: Method and device for measuring the Abbe number in a process liquid. Light generates successively at wavelengths of 486.1 nm, 589.3 nm and 656.3 nm and different light wavelengths are directed successively through a measuring window in the process liquid so total reflection occurs at each wavelength on the measuring window surface and process liquid. Partial light reflected at each wavelength is directed to a sensor, whereby an image forms on the sensor surface; between light and dark boundary region corresponding to each wavelength critical angle, in which total reflection occurs. At each wavelength between light and dark boundary region detection by image analysis. At each wavelength, dependency between light and dark boundary region and refractive-index of process liquid measurement is detected, the Abbe number by refractive-index values obtained from: V D = n D - 1 n F - n C ; nD=refractive-index of process liquid to measure at 589.3 nm; nF=refractive-index at 486.

Abstract: An exemplary arrangement includes a prism-shaped measuring window, which has a measuring surface adapted to contact a substance being measured. A first surface is adapted to direct light originating from a light source to the measuring surface through the measuring window. A second surface is adapted to direct totally reflected light from an interface between the measuring surface in contact with the substance being measured and a substance being measured outside of the measuring window. A first lens arrangement is adapted to focus the light from the light source on the first surface. A second lens arrangement is adapted to focus the totally reflected light passing through the second surface to a device used for analysis. A lens in each of the first and second lens arrangements closest to the measuring window is integrated into the measuring window and establishes optical refractive power in the first and second surfaces.

Abstract: A method and an arrangement are disclosed in connection with a measurement arrangement of optical parameters of a separate sample taken from a process liquid, in which method a sample is taken from the process liquid. The sample can be arranged into a sample vessel provided with at least one measurement window, and optical parameters of the sample in the sample vessel are measured through the measurement window. In the sample in the sample vessel, a flow is produced which can be used to mitigate (e.g., prevent) the measurement window surface in contact with the sample from getting dirty. A back-and-forth flow can be produced in the sample residing in the sample vessel by means of pressure variation focused on the sample, and the back-and-forth flow can be focused on the surface of the optical measurement window.

Abstract: Method and device for measuring the Abbe number in a process liquid. Light generates successively at wavelengths of 486.1 nm, 589.3 nm and 656.3 nm and different light wavelengths are directed successively through a measuring window in the process liquid so total reflection occurs at each wavelength on the measuring window surface and process liquid. Partial light reflected at each wavelength is directed to a sensor, whereby an image forms on the sensor surface; between light and dark boundary region corresponding to each wavelength critical angle, in which total reflection occurs. At each wavelength between light and dark boundary region detection by image analysis. At each wavelength, dependency between light and dark boundary region and refractive-index of process liquid measurement is detected, the Abbe number by refractive-index values obtained from: V D = n D - 1 n F - n C ; nD=refractive-index of process liquid to measure at 589.3 nm; nF=refractive-index at 486.

Abstract: A method and measuring sensor are disclosed for measuring temperature, the method including arranging a measuring element of the sensor into thermal contact with a process liquid being measured, and directing a measuring signal received from the measuring element onward by measuring conductors connected to the measuring element. Close to the measuring element, terminal areas are established which are arranged in unrestricted thermal contact with the process liquid being measured, and the measuring conductors are connected to the measuring element through the terminal areas.

Abstract: The invention relates to a measuring sensor for measuring temperature in a chemical process, the measuring sensor comprising a measuring element supported on the frame of the measuring sensor and arranged in thermal contact with the process being measured, and measuring conductors connected to the measuring element for directing a measuring signal onward. The frame of the measuring sensor is made of mineral material.

Abstract: The invention relates to a measuring sensor for measuring temperature in a chemical process, the measuring sensor comprising a measuring element supported on the frame of the measuring sensor and arranged in thermal contact with the process being measured, and measuring conductors connected to the measuring element for directing a measuring signal onward. The frame of the measuring sensor is made of mineral material.

Abstract: A method and measuring sensor are disclosed for measuring temperature, the method including arranging a measuring element of the sensor into thermal contact with a process being measured, and directing a measuring signal received from the measuring element onward by measuring conductors connected to the measuring element. Close to the measuring element, terminal areas are established which are arranged in unrestricted thermal contact with the process being measured, and the measuring conductors are connected to the measuring element through the terminal areas.

Abstract: A measuring device for measuring the rheological properties of a substance, said measuring device comprising a sensor to be arranged in the process, a drive and a shaft for rotating the sensor in the process, and a measuring element for measuring the torque produced between the sensor rotating in the process and the process. To perform a reliable measurement, the sensor is a piece symmetrical with respect to the direction of rotation, the mechanical construction and the drive are symmetrical with respect to the direction of rotation, and the torque-measuring element is symmetrical in its structure in such a manner that it produces signals that are equal in their absolute value in the opposite directions of rotation of the sensor.

Abstract: An arrangement for cleaning an optical window in an instrument such as a refractometer located in-line in a continuous or batch process, comprising a nozzle for spraying under high pressure a harmless cleaning medium onto the optical window. The nozzle is firmly fixed in a nozzle frame, the frame itself being firmly attached to the instrument in the vicinity of the optical window. The nozzle is recessed in the frame. The invention achieves cleaning of the optical window without mechanical parts or strong solvents, and does not require removal of the instrument from its in-line position.

Abstract: An arrangement for displacing a measuring head of a measuring device into and from a process space. The arrangement comprises a valve element and a measuring device. The measuring device comprises a tube, at one end of which there is a measuring head. The measuring device is arranged to be moved through the valve element to a position in which the measuring head extends into the process space and again to a position in which the measuring head is not in connection with the process space. To effect a controlled displacement of the measuring device, the arrangement comprises two threaded bars parallel to the displacement direction of the measuring device and fastened to the valve element as well as two threaded stop elements arranged in the measuring device. The motion for the displacement of the measuring device has been arranged to be effected by relative motion between the stop elements and the threaded bars.

Abstract: The invention relates to a method for the illumination of particles contained in a medium for an optical analysis, and to an optical particle analyser. The medium (1) thereby makes contact with a window (2), and a light beam illuminating the particles is directed into the medium through the window in order to form an image of the particles. In order to enable an accurate quantitative and qualitative analysis carried out directly from the medium, the light beam is modified into a beam (5) having a predetermined thickness in the direction of the normal of the window. The beam (5) is directed to advance in the medium containing the particles close to and substantially in parallel with a window surface (6) making contact with the medium in order to illuminate particles (10) contained in a predetermined volume part (9) of the medium for the formation of an optical image (8).

Abstract: The invention relates to a measuring window for a process refractometer. Process refractometers are commonly used in the industry for continuous measurement of the concentration of a solution. The wall of the refractometer facing the process solution is provided with a window which must satisfy the requirement that the passage of light rays satisfies certain criteria, that the sealing is reliable, that the fastening is firm and that the wall facing the process and the window form a planar surface. The transparent portion of the window according to the invention comprises a roof prism embedded in a V-shaped groove in the process wall. Each wall of the V-groove is provided with a sealing abutting against the prism, and the third side of the prism forms a continuous plane with the process wall.