Abstract: According to an example aspect of the present invention, there is provided a method, comprising: controlling suction with predetermined force in a known measurement area to a moving cardboard or paper web in a manufacturing process, detecting on-line measurement information on deviation of the moving cardboard or paper web in the manufacturing process caused by the suction with predetermined force in the known measurement area, and determining elastic modulus of the moving cardboard or paper web in the manufacturing process on the basis of the measured deviation.

Abstract: A method of measuring properties of a moving cellulose, paper or board sheet. A first parameter of a first resonance caused by the moving sheet in a frequency range 1 GHz to 25 GHz of electromagnetic radiation is measured. A second parameter of an electromagnetic signal transmitted between at least a pair of transceiver parts of a transceiver sensor located on opposite sides of the moving sheet through the moving sheet is measured in a frequency range 25 GHz to 1000 GHz. A minimum difference between the frequency ranges related to the first parameter and the second parameter being at least 5 GHz. Both the dry stuff content and the weight of water per unit of area are determined on the basis of the first parameter, the second parameter and available information related to a distance travelled by the electromagnetic signal.

Abstract: According to an example aspect of the present invention, there is provided a method, comprising: controlling suction with predetermined force in a known measurement area to a moving cardboard or paper web in a manufacturing process, detecting on-line measurement information on deviation of the moving cardboard or paper web in the manufacturing process caused by the suction with predetermined force in the known measurement area, and determining elastic modulus of the moving cardboard or paper web in the manufacturing process on the basis of the measured deviation.

Abstract: A method of measuring properties of a moving cellulose, paper or board sheet. A first parameter of a first resonance caused by the moving sheet in a frequency range 1 GHz to 25 GHz of electromagnetic radiation is measured. A second parameter of an electromagnetic signal transmitted between at least a pair of transceiver parts of a transceiver sensor located on opposite sides of the moving sheet through the moving sheet is measured in a frequency range 25 GHz to 1000 GHz. A minimum difference between the frequency ranges related to the first parameter and the second parameter being at least 5 GHz. Both the dry stuff content and the weight of water per unit of area are determined on the basis of the first parameter, the second parameter and available information related to a distance travelled by the electromagnetic signal.

Abstract: A measuring device includes a first optical sensor row and a second optical sensor row between which a planar object to be measured is placed. The direction of the first sensor row and the direction of the second sensor row differ from one another. Each sensor of the first sensor row forms data representing a distance between the object to be measured and the sensor. Each sensor of the second sensor row forms data representing a distance between the object to be measured and the sensor in order to determine at least one property of the object to be measured on the basis of the data.

Abstract: The measuring device is an on-line measuring device including a pressure generator and a sensor, by which is determined porosity of paper or board, constituting an object of measurement, by directing known suction effect to the paper or board and measuring low pressure produced by the suction effect for the determination of porosity.

Abstract: A method for the calibration of measuring equipment, and measuring equipment. The measuring equipment comprises at least one first sensor, at least one second sensor and at least one reference piece. When the measuring equipment is calibrated, a moving web is supported against the reference piece and the reference piece with the moving web supported thereto is moved to different distances from the first sensor and the second sensor. Further, a distance between the first sensor and the moving web and a distance between the second sensor and the reference piece is measured at least for two different distances, and the first sensor and the second sensor are calibrated to be uniform in relation to the movement of the reference piece.

Abstract: A method for the calibration of measuring equipment, and measuring equipment. The measuring equipment comprises at least one first sensor, at least one second sensor and at least one reference piece. When the measuring equipment is calibrated, a moving web is supported against the reference piece and the reference piece with the moving web supported thereto is moved to different distances from the first sensor and the second sensor. Further, a distance between the first sensor and the moving web and a distance between the second sensor and the reference piece is measured at least for two different distances, and the first sensor and the second sensor are calibrated to be uniform in relation to the movement of the reference piece.

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: 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.