Abstract: A method and an apparatus for measuring the amount (CW) of a coating (2) on a paper web (1). The amount (CA) of at least one component in the coating (2) on the paper web (1) is measured and the composition (CC) of the coating (2) to be transferred to the paper web (1) is determined. The amount (CW) of the coating (2) on the paper web (1) is determined on the basis of the amount (CA) of at least one component in the coating (2) on the paper web (1) and the composition (CC) of the coating (2) to be transferred to the paper web (1).

Abstract: The invention relates to a method in the process of manufacturing and/or finishing a fibre web, in which method said continuous and moving web, and/or a moving means related to the processing of the web, is monitored by at least one optical spectrum separating measurement device to determine at least one quality variable of said object for the purpose of controlling the quality or condition. According to the invention, spectral data is collected in synchronization with the movement from the object which is being examined and is in a progressive and/or rotating movement, by measuring electromagnetic radiation, which has been transmitted, reflected, or otherwise emitted by the object, in a temporally and spatially resolved manner.

Abstract: A method and an apparatus for controlling a moisture profile of a paper web, in which the moisture profile of the paper web prior to drying is measured. The measurement is carried out with a measuring device, which measures a cross-direction profile of the web substantially simultaneously. On the basis of the measurement, the moisture profile of the paper web is controlled prior to drying the paper web.

Abstract: The invention relates to a method and an apparatus for measuring a coating from paper or board. The measurement is carried out by one detector at different times or by two detectors simultaneously. IR radiation directed at the coating and radiation emerging from the coating are chopped synchronously in blocks. A wavelength band sensitive and insensitive to the absorption are bandpass filtered and measured in both the MIR and NIR region. The absorption strength is measured in a digital signal processing block by comparing the radiation sensitive to absorption to the radiation insensitive to absorption, and the amount of each coating component is determined in the digital signal processing block on the basis of the absorption strength.

Abstract: A method and an apparatus for controlling a moisture profile of a paper web, in which the moisture profile of the paper web prior to drying is measured. The measurement is carried out with a measuring device, which measures a cross-direction profile of the web substantially simultaneously. On the basis of the measurement, the moisture profile of the paper web is controlled prior to drying the paper web.

Abstract: The invention relates to a method and an apparatus for measuring the amount of silicone coating on a moving paper or board web. In the invention, the characteristics of the coating (4a) are measured by means of reflection measurement or transmission measurement. The amount of the silicone in the coating is measured by measuring an absorption peak that is characteristic of the silicone in the mid-infrared range.

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: The invention relates to a method and an apparatus for measuring a coating from paper or board. The measurement is carried out by one detector at different times or by two detectors simultaneously. IR radiation directed at the coating and radiation emerging from the coating are chopped synchronously in blocks. A wavelength band sensitive and insensitive to the absorption are bandpass filtered and measured in both the MIR and NIR region. The absorption strength is measured in a digital signal processing block by comparing the radiation sensitive to absorption to the radiation insensitive to absorption, and the amount of each coating component is determined in the digital signal processing block on the basis of the absorption strength.

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: In a paper machine which comprises process elements and a measuring beam, the measuring beam is arranged at least at one paper machine process element so that a measuring device for measuring quality properties of a paper web is arrangeable in the measuring beam. The paper machine process element is e.g. a blow box, which is arrangeable in a dryer unit of the paper machine between drying cylinders to blow air via at least one blow air channel provided in the blow box to guide the moving paper web and/or to assist drying.