In a starch concentration measurement, a liquid sample is conducted from a liquid sample such as pulp suspension or filtrate of a paper, board or tissue process. An iodine solution is added to the sample, and a light absorbance or transmittance of the sample is measured at a wavelength longer than about 650 nm, for example longer than about 700 nm. The measured absorbance or transmittance of the sample is converted into the starch concentration of the sample by a predefined correlation between a starch concentration and a light absorbance or transmittance.

A method includes forming an aqueous fibre suspension including cellulosic fibres from one or more raw material flows, and applying at least one chemical and/or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension is in the intermediate residence entity at least a minimum delay time. A final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

The present invention provides a method for determining carbonyl ratio and/or concentration of oxidized nanofibrillar cellulose in a sample. In accordance with the invention oxidized nanofibrillar cellulose comprised in the sample is enzymatically hydrolyzed into oxidized cellobioses which are specific markers to oxidized nanofibrillar cellulose. The cellobioses may be then analyzed and quantified to reveal the amount of oxidized nanofibrillar cellulose in the sample. A method for determining the concentration of oxidized nanofibrillar cellulose in a sample comprises steps of providing an analytical sample of material comprising oxidized nanofibrillar cellulose; hydrolyzing the analytical sample to breakdown products of oxidized nanofibrillar cellulose in presence of one or more enzymes; subjecting the breakdown products to a separation analysis to reveal the relative amounts of the breakdown products; and determining the concentration of oxidized nanofibrillar cellu-lose.

In a starch concentration measurement, a liquid sample is conducted from a liquid sample such as pulp suspension or filtrate of a paper, board or tissue process. An iodine solution is added to the sample, and a light absorbance or transmittance of the sample is measured at a target wavelength. The measured absorbance or transmittance of the sample is then converted into the starch concentration of the sample.

Provided is method for evaluating a cellulose nanofiber (CNF) dispersion, the method including: (1) a step of preparing 1.0 mass% of a CNF aqueous dispersion; (2) a step of adding a coloring material into the CNF aqueous solution and stirring with a vortex mixer; (3) a step of sandwiching a film of the coloring material-containing CNF aqueous dispersion between two glass plates such that said film has a thickness of 0.15 mm; (4) a step of observing, with a microscope, the film of the coloring material-containing CNF aqueous dispersion sandwiched between the two glass plates; (5) a step of sorting observed aggregates by size (diameter along major axis) thereof; and (6) a step of calculating a CNF dispersion index from the number of sorted aggregates and evaluating the dispersibility of the CNF aqueous dispersion.

A method and apparatus for measuring the moisture content of pulp material on a wire in an installation for producing paper. The apparatus includes a measuring device for measuring the moisture content of the pulp material. The apparatus has a moisture sensor, a control and data processing unit assigned to the measuring device, and a transmitting and receiving device and/or a connection for a data line for transmitting the measured data to the control and data processing unit. The measuring device for measuring the moisture content of the pulp material includes a pressure measurement device for determining and displaying a pressure range with which it is being pressed against the wire. The contact pressure is controlled and taken into account during the measurement of the moisture content.

The present invention relates to a device, system and method to measure tackiness of a substance, such as pulp, with an on-line or an in-line sensor having a transparent plate with a surface where tacky particles can attach. Attached particles are identified by a camera behind the plate. The camera is focused to detect stationary particles attached to the surface. Measurement is performed directly from a process stream or from a sidesteam and the plate does not need to be removed from the process for the measurement. The plate material may be plastic, such as polycarbonate or acrylic. Additionally, the flow speed may be kept be low, e.g. <0.1 m/s at the measurement position, and/or there may be a stagnation point of flow at or near measurement where the flow speed approaches zero.

A measuring device that makes it possible to improve precision and stability is provided. In a measuring device 50, a microwave receiving unit 52 is disposed behind a microwave transmitting unit 51 with respect to a powder object 2, and the microwave transmitting unit 51 and the microwave receiving unit 52 are each enclosed by a waveguide box. A waveguide box 6 for the transmitting unit is smaller than a waveguide box 8 for the receiving unit, and is enclosed by the waveguide box 8 for the receiving unit. An opening portion 7 of the waveguide box 6 and an opening portion 9 of the waveguide box 8 are mounted on a flat window material 5, and are aligned. The window material 5 is in contact with the powder object 2. Microwaves 3 transmitted from the microwave transmitting unit 51 are reflected by the powder object 2, are received, as scattered microwaves 4, by the microwave receiving unit 52, and are measured.

An apparatus for optically measuring fluidal matter having fluid as medium and particles non-dissolved in the medium wherein the apparatus comprises a measurement chamber, which is configured to contain the fluidal matter, and a nozzle. The nozzle receives flowable matter and emits a jet of the flowable matter towards or fromwards an optical detector which is associated with the measurement chamber and receives optical radiation from the fluidal matter in the measurement chamber.

Vibration sensors can be used in paper making systems and methods to determine various aspects of the paper making operation. Vibration sensors, for example, positioned on cleaning blades configured to clean various deposits off of rollers in a paper making system can output vibration data that can be indicative of the vibration of the blade. The vibration data can be analyzed in order to characterize the cause of the vibration and/or the location of the vibration within a paper making system. If the vibration data satisfies a predetermined condition, a corrective action can be initiated. Different corrective actions can be initiated based on the characterized cause and/or location of the vibration in order to effectively improve the operation of the system while minimizing costly system shut downs and major maintenance.