Abstract: An apparatus and method are provided in which direct ohmic connection is made to a comminution device (e.g., a wood chip or pulp refiner) to obtain transient voltages, existing on the refining elements, that are directly related to fiber impacts. These voltages are characterized by severity (S) (i.e., magnitude), rate (N), rise time (RT) and polarity (.+-.P). The characteristics of these voltages taken separately and/or in mathematical combinations predict the properties of refined wood chips and pulps, i.e., freeness, tensile strength, tear, burst, breaking length and fiber length. Signal characteristics further track refiner plate wear and detect the occurrence of "critical gap" as well as the onset of plate clash.

Abstract: A temperature-compensated apparatus and method for determining the percentage of solid particles in a suspension (consistency) is provided. A source of diffused radiant energy is directed toward a suspension to be measured. The portion of the energy which is forward-scattered by the suspension is detected and a first signal indicative of the magnitude of the forward-scattered energy is produced. The portion of energy which is back-scattered by the suspension is detected and a second signal indicative of the magnitude of back-scattered energy is produced. The first and second signals are combined at a predetermined ratio to produce a feedback signal used to control the intensity of energy emitted from the radiant energy source. The intensity of energy emitted from the source is a function of the forward-scattered and back-scattered energy and is directly proportional to the consistency of the suspension being measured.

Abstract: An apparatus and process are disclosed for examining a moving web of paper to determine the optical parameter of "formation" and the physical parameter of "roughness". The apparatus includes an optical system which forms an area of the web, with a first light source directing light through the moving web area from a back surface thereof, and a second light source directing light obliquely to the web area from the front surface thereof. A signal processing device determines the root-mean-square of the quotient resulting from the difference in received radiation from two spatially adjacent areas of the detectors divided by the sum of the received radiation from four spatially adjacent areas of said detectors to provide an output signal corresponding to formation or roughness of the paper web.

Abstract: A particle refining process is controlled in response to detected electron transfer phenomena. Pulses of electromagnetic radiation emanating from a refiner during a refining process are detected. The detected radiation is produced by dissociation and recombination phenomena in the particles being refined. The detected pulses are processed to obtain data indicative of the performance of the refining process. In particular, the mean pulse duration and mean energy per unit time of the detected pulses are computed. A process control signal is produced in response to the data, and the operation of the refiner is controlled with the process control signal to optimize the refining process.

Abstract: A radiation sensor provides on-line measurement of web MD/CD fiber orientation ratio, formation indexes of multiple spatial frequencies, and optical density as it relates to basis weight. A light source illuminates one side of a substrate to be measured. The radiation passing through the substrate is detected by a pair of detectors having fields of view along narrow strips which are perpendicular to each other. The combined field of view is scanned in a repetitive pattern traversing an area on the substrate to be analyzed. The detector outputs are processed to provide fiber orientation ratio, formation, and basis weight measurements.

Abstract: A transducer mounting assembly is provided for use in conjunction with apparatus for measuring the percentage of solid particles in a suspension flowing through a pipe. A hinged collar is adapted to be secured around a section of pipe. A radiant energy source is mounted at a first position on the circumference of the collar for radiating diffused radiant energy into the pipe. A first radiant energy detector is mounted at a second position on the circumference of the collar for sensing diffused energy in the pipe which is forward-scattered when a suspension flows therethrough. A second radiant energy detector is mounted at a third position on the circumference of the collar adjacent the first position for sensing diffused energy in the pipe which is back-scattered by a suspension flowing therethrough. A connector is provided for connecting the radiant energy source and detectors to a measuring apparatus.

Abstract: An apparatus and method for determining the percentage of solid particles in a suspension (consistency) is provided. A source of diffused radiant energy is provided which energy is directed toward a suspension to be measured. The portion of the energy which is forward-scattered by the suspension is detected and a first signal indicative of the magnitude of the forward-scattered energy is produced. The portion of energy which is back-scattered by the suspension is detected and a second signal indicative of the magnitude of back-scattered energy is produced. The first and second signals are combined at a predetermined ratio to produce a feedback signal used to control the intensity of energy emitted from the radiant energy source. The intensity of energy emitted from the source is a function of the forward-scattered and back-scattered energy and is directly proportional to the consistency of the suspension being measured.

Abstract: Apparatus for sensing the distance from a reference point to a remote object comprises a light source and optics to project light from the light source onto the remote object. One component of the optics is a movable mirror which is used to position the projected light on a remote object. A sensor is provided to detect the position of the projected light on the remote object. In response to position information from the sensor, control circuitry produces a drive signal which controls a galvanometer. The galvanometer shaft is attached to rotate the mirror. When the mirror has been positioned such that the projected light impinges on the remote object at a predetermined location, the value of the drive signal can be used to compute the distance to the remote object by triangulation.

Abstract: An apparatus and method for dynamically monitoring the gap between the refining surfaces of first and second relatively rotating metallic refining members. At least one of the refining members is mounted to a first rotatable shaft which is supported in a housing by lubricated bearing means. When the refining members are in rotating relation, an electrical impedance exists across the gap. The value of the impedance is dependent on the size of the gap. An alternating electrical current is passed through the gap and the voltage across the gap is monitored to provide an indication of the size of the gap. The voltage across the gap can also be used as one input to a circuit which controls the size of the gap by driving an electro/hydraulic system.

Abstract: A flying spot is used to scan a web completely across the web from a leading to a trailing edge plus an additional distance on each side with the apparatus being initiated automatically as the leading edge is reached and ceasing an output when the trailing edge is reached. The web might be a paper web, for example, being scanned to determine the two edges, and also to determine defects including holes and wrinkles in the web. The flying spot is rectangular with the length of the rectangle parallel to the moving direction of the web and this flying spot rectangle traverses from one side to the other of the web. A hole in the web gives less than average reflected illumination to a detector, whereas a wrinkle gives increased illumination to the detector. The circuit differentiates the raw signal so that a hole or dark signal, gives a positive and then a negative going pulse, whereas a wrinkle, or lighter signal, gives a negative going pulse followed by a positive pulse.