Abstract: A method in the process of manufacturing and/or finishing a fiber web (11), in which method the Continuous and moving web (11), and/or a moving device (16, 17) related to the processing of the web (11), is monitored by one or more thermal cameras (10) of the infrared range or a corresponding detector/detectors for the purpose of controlling the quality or condition. A substantially continuous two-dimensional thermal image or continuous thermal chart (20) of an object (11, 16, 17) being monitored and in a propagating and/or rotating movement is formed by said detector/detectors in a time-resolved manner and in synchronization with the movement of the object (11, 16, 17) in the direction of the movement.

Abstract: The invention relates to a method and an arrangement for performing a measurement of a continuous sheet. At least one measurement of the sheet is performed by at least one sensor, an estimate of the sampling function of the sensor being available. The solution comprises means for performing deconvolution using at least one iteration of an algorithm which corresponds to the deconvolution, and the means are arranged to perform the deconvolution of the at least one measurement with the estimate of sampling function. The solution can be applied in a CD-measurement of a continuous sheet. The solution can also be applied in controlling production of a continuous sheet.

Abstract: A device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, comprising an infrared lighting device suited for illuminating the web of paper with infrared light and a detector device for detecting light reflected or transmitted by the web of paper which is provided with a light input portion. The infrared lighting device is provided with a light source in the form of a long, rod-shaped infrared emitter, the light source being accommodated in a housing having a front plate facing the web of paper. An exit window, through which the light from the light source passes to impinge upon the web of paper, is tight-fittingly received in an aperture in the front plate.

Abstract: The invention relates to a method and a controller for controlling a process. The process output signal or the control output signal comprises a functional variable and the process output signal is defined for at least one moment of time. The controller performs a functional operation on the signal comprising the functional variable to preserve the functional information. The controller also forms a cost function of at least the signal comprising the functional variable with the preserved functional information and performs an optimization of the cost function in which the preserved functional information is included. Finally, based on the optimization of the cost function the controller forms at least one process input signal for at least two separate moments of time for controlling the process.

Abstract: The invention relates to a method and a device for measuring the amount of coating on a moving substrate. Reflection measurement is used in the invention for measuring the properties of a coating. The amount of calcium carbonate in the coating is measured by measuring an absorption peak of calcium carbonate at a wavelength of about 3.95 micrometers and/or the amount of kaolin is measured by measuring an absorption peak of kaolin at a wavelength of about 2.7 micrometers.

Abstract: A method and equipment for measuring the tension of a moving web. The tension of the moving web is measured by means of a measuring element provided with a guide surface which the moving web is guided to pass such that the web forms an air cushion of the air it carries between the web and the guide surface. Measuring devices are arranged at a distance from one another in connection with the measuring element in the cross direction of the web for measuring a variable representing the tension of the moving web. The measuring element is moved back and forth in the cross direction of the web such that the tension profile of the web is measured at least on a part of the web width by means of the measuring devices arranged in connection with the measuring element.

Abstract: In the method for monitoring a paper web or the like, the properties and state of the paper web (W) or the like, travelling in a paper machine or in a finishing machine for paper are monitored by observing the travelling paper web with one or more image-forming systems based on camera technique, and the properties of the web are measured with a system comprising one or more physical on-line measurement methods. The systems use different observation devices for monitoring the web. At least two different systems, which use different observation devices, are integrated at least partly by placing the web observation devices in the same machine part, by using software of different systems on the same substation (8), and/or by using the same user interface software for both systems in the workstation (9) in the user interface. The observation devices of different systems can be cameras (2) and sensors, which are placed in the same measurement beam or frame (1) extending across the web (W).

Abstract: A method and an apparatus for adjusting a chemical dosage of a pulp processing stage. The method comprises measuring a change in a variable in dependence on the chemical dosage and the chemical dosage to be added, and determining a model describing the change in the variable as a function of the chemical dosage. A performance index is determined for the new model to be compared with the performance index of certain previously determined models. The model that produced the best performance index is put to use.

Abstract: The measuring device is arranged to measure at least one property of a moving web. The measuring device includes at least one measuring head with at least one measuring element arranged in a flexible membrane that surrounds the measuring element and is arranged in connection with the measuring head such that the measuring element is movable by means of the flexible membrane perpendicularly to the moving web. The turning effect, which is caused by the pressure of the air conveyed with the moving web, and directed in the travel direction of the web at least in front of the measuring element on the web side of the flexible membrane, and turns the measuring element, is prevented by at least partly changing the amount and/or flow direction of the air conveyed with the web moving to the measuring element.

Abstract: The invention relates to a method and an apparatus according to the method. A sample is illuminated by a band of optical radiation the illumination state of which is variable as a function of time. Reference measurements of the spectrum of the optical band illuminating the sample are made at least at three separate instants of time. A spectrum of a band of the optical radiation that has interacted with the sample is measured at the corresponding separate instants of time as the reference measurement, and the radiance transfer factor matrix of the sample is estimated from the set of reference measurements and the set of sample measurements.

Abstract: The measuring device comprises at least one measuring head having a reference part, which comprises a reference surface against which the moving web is supported. The reference surface comprises a measuring area in the inside of which the property of the web is measured. The reference part is arranged in connection with the measuring head in such a way that below the reference part, there is a substantially open air space. The measuring head comprises means for generating negative pressure in the air space below the reference part, and the reference part comprises holes formed through it, in such a way that the negative pressure generated in the air space affects through the reference part the space between the reference surface and the moving web in such a way that the web is supported against the reference surface substantially over the whole area of the measuring area.

Abstract: An on-line condition monitoring system for the real-time observation of a number of monitored objects comprises a sensor arranged at each object to generate signals representing the condition of the object, a substation for receiving signals from the object at certain measurement intervals and transmitting measurement data to a monitoring unit which has a processing unit and one or more workstations at which the condition of different objects can be observed, and a data network. The substation is further arranged to receive signals during a longer period from an object, which has been put into particular real-time observation. The substation and/or the workstation is arranged to process the signals received by the substation and to generate and present calculation results to the operator. The workstation is arranged by means of real-time signal analysis user interface software to display to the operator the measured signals and the results calculated from them.

Abstract: The invention relates to a method and a measuring arrangement for determining gloss of paper or paperboard. The paper or paperboard surface is illuminated with collimated light substantially parallel with the normal of the paper or paperboard surface. An image is produced from the paper or paperboard surface by means of reflected optical radiation. The reflected optical radiation is used for producing an image of the paper or paperboard surface onto the pixels of the camera's detector surface, each of the pixels imaging an area in the order of micrometers of the paper or paperboard surface. An aperture provided in front of the camera is used for adjusting the incidence angles of the reflected radiation, which affects the measurement of gloss. Gloss of paper or paperboard is measured on the basis of the intensity of the pixels on the camera's detector surface.

Abstract: A measuring probe in a paper measuring apparatus is kept at a distance from the surface of the paper by feeding medium between the paper and a surface of the measuring probe through a feed hole in the surface of the measuring probe. The pressure of the supplied medium, the dimensions of the feed hole and measuring probe, and the distance of the probe surface from the paper are arranged such that after the medium is discharged from the feed hole, the rate of the flowing medium increases so as to produce an underpressure, which generates a force tending to move the paper and the measuring probe toward each other. The discharge of the medium from the feed hole produces an opposite force urging the paper and probe away from each other, and the measuring probe and paper settle in a state of equilibrium determined by the two forces.

Abstract: The invention relates to a method and an apparatus for measuring the properties of paper from a moving paper web in a paper machine. An infrared beam is directed to the paper web. The infrared beam, passed through or reflected from the paper web, is split into wavelength components with a spectrograph, and signals of the different wavelength components are measured, and the properties of paper are determined on the basis of the signals.

Abstract: A device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, comprising an infrared lighting device suited for illuminating the web of paper with infrared light and a detector device for detecting light reflected or transmitted by the web of paper which is provided with a light input portion. The infrared lighting device is provided with a light source in the form of a long, rod-shaped infrared emitter, the light source being accommodated in a housing having a front plate facing the web of paper. An exit window, through which the light from the light source passes to impinge upon the web of paper, is tight-fittingly received in an aperture in the front plate.

Abstract: The invention relates to a device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, with an infrared lighting device suited for illuminating the web of paper with infrared light and provided with a light exit portion, with a detector device for detecting infrared light reflected or transmitted by the web of paper which is provided with a light input portion and with a housing a) which is arranged in immediate proximity to the paper web, b) which is provided with a front face facing the web of paper and c) which accommodates the light exit portion and/or the light input portion provided with optical fibers. A plurality of n spherical lenses is arranged in a sealed manner in the front face, said spherical lenses being each optically coupled to an allocated optical fiber within the housing, said spherical lenses constituting, together with the corresponding optical fibers, the light exit portion and/or the light input portion.

Abstract: An infrared detector device for a device for detecting properties of a moving web of paper, more specifically for a device for controlling production in the paper making process, the detector device being provided, on the one side, with a polychromator that receives, on its receiving side, light coming from the web of paper and, on the other side, with an infrared detector with a matrix of infrared sensitive photoconductors, an evaluation electronic unit with one memory assigned to a respective one of the photoconductors of the matrix being connected downstream thereof. An additional source of light that can be controllably switched on and off between a first light intensity and a second light intensity which is greater than the first one uniformly illuminates the infrared detector for deriving correction values for correcting the signals from each of the photoconductors during a measurement.

Abstract: A method and an apparatus for identifying mapping of a paper machine by means of a mapping test. The invention comprises forming a mapping model which takes the linear and non-linear shrinkage of a paper web into account. The mapping test result is analyzed to form a non-linear shrinkage profile and a linear mapping error from it. The linear error and the non-linear shrinkage profile thus obtained are used in the mapping model.

Abstract: The invention relates to a method and apparatus for measuring the tension of a moving web. In the invention, a measuring beam (2)is curved so that a web moving over or under the measuring beam (2) forms an air cushion (3) of the air it transports between the measuring beam (2) and the web (1). The web (1) causes a force effect transmitted by the air cushion on the measuring beam (2). The tension of the web (1) is measured by measuring the force caused by the web (1) and transmitted by the measuring beam (2).