Abstract: A contacting thickness gauge comprising a unique surface follower (46). The bottom surface (56) of the surface follower (46) has both contacting areas (64,66) and non-contacting areas (62). The surface follower (46) is in substantially continuous contact with a moving sheet (2) and embodies an electrically conductive target having a target surface that intersects a magnetic field but is substantially free from contact with the sheet during normal operation. The surface follower (46) is designed to minimize damage to the sheet (2) that would otherwise occur from contact between the surface follower and a protruberance of the sheet, and to preserve the characteristics of the target surface.

Abstract: An apparatus and process for measuring physical parameters of sheet material via infrared absorption phenomena is disclosed. The invention employs an integral filter-detector package comprising at least two optical filter-detector combinations. The package is contained within a conventional sensor housing which traverses back and forth across the sheet material. The package may comprise an additional filter-detector combination that is selected to produce a detector response having a significantly higher signal-to-noise ratio than the response of remaining detectors. The former response is used in combination with synchronous detectors to provide a reference of the general shape and phase of the latter responses in the absence of high noise.

Abstract: A hooded air shower system for controlling the diameter profile of a rotating cylinder. Air is supplied to an air chamber and then channeled into a plurality of conduits that correspond to a plurality of cross-machine zones of the cylinder. The air temperature is regulated within each conduit and separate channeling is maintained until the air is directed to the cylinder. An obstructing device substantially restricts movement of the air along the cylinder to one circumferential direction, and a given portion of directed air moves along substantially the entire circumferential range of the cylinder that is subtended by the hood.

Abstract: A process and apparatus for measuring moisture content of moisture-stratified sheet material such as paper is disclosed. The effective reflectivities of two areas of an infrared moisture sensor that generally face opposite surfaces of the sheet are made significantly different, so that the sensitivity of the measurement to conditions prevailing in a high-moisture stratum of the sheet is increased.

Abstract: Disclosed are apparatus and methods for producing electrical signals that can be used to measure the speed of ultrasound in a moving web of paper. The apparatus employs a hollow cylinder in which a plurality of transducers are positioned to contact the web. Power supplied to the cylinder through mercury slip is filtered by power conditioning circuitry in the interior of the cylinder, thus enabling the delivery of clean electrical pulses to the emitting transducers. Signals from the receiving transducers are delivered to voltage-to-frequency converter circuitry in the interior of the cylinder, and the resulting electrical frequency signals are converted to optical frequency signals. The optical signals are then communicated across an air gap to receptors which are external to the cylinder. Thus, signals from which measurements of the speed of ultrasound can be derived are provided substantially free from noise generated by transmission through slip rings.

Abstract: A transducer for transmitting or receiving ultrasound in on-line applications is disclosed. The transducer comprises a piezoelectric element having the shape of a parallelepiped, and a nosepiece rigidly attached to a surface of the element and adapted for contact with sheet material through which ultrasound is propagated.

Abstract: A traveling mat (10) of glass fibers that have been coated with a resinous binder is measured so as to determine quantitatively the mass of binder per unit area of the mat, by directing into the traveling mat gamma rays (26) from a first radiation source (28) comprising americium-241 isotope, also directing into the traveling mat isotopic X-rays (30) from a second radiation source (32) comprising curium-244 isotope, detecting (at 22) the gamma rays from the traveling mat to produce a first response (R.sub.A), detecting (at 24) the isotopic X-rays from the traveling mat to produce a second response (R.sub.C) and forming (at 48) a combination of the first and second responses so as to produce a third response (B) that is indicative of the mass of the binder and substantially independent of the mass of the glass fibers.

Abstract: The moisture in paper is measured using a first set of infrared radiation wavelengths that have about the same absorption coefficients for the fiber constitutent of the paper but have substantially different absorption coefficients for the moisture contained in the paper, and a second set of infrared wavelengths that have about the same absorption coefficients for the moisture contained in the paper but have substantially different absorption coefficients for the fiber constituent, both sets of infrared radiation wavelengths being affected to about the same extent by a variable scattering characteristic of the fiber and are also affected to about the same extent by the variable amount of a broadband absorber such as carbon in the paper.

Abstract: For measuring a property such as caliper of a traveling sheet, a sensor body and a target body are located on opposite sides of the sheet and constrained (e.g., by gas bearings) along a sensor path intersecting the path of the sheet. Gas bearings maintain these bodies at, substantially constant distances from the opposite surfaces of the sheet while permitting them to move in response to the position and thickness of the sheet. An active sensor element aboard the sensor body and a passive sensor element aboard the target body interact through the sheet to produce aboard the sensor body a response dependent on the sheet property. Manifestations of this response, such as light beam modulations, are produced, without solid bodily connections, at a location spaced from the sensor body where the manifestations are detected to produce a sheet property-indicative signal.

Abstract: A device for control of the slice opening of a slice on a headbox contains several jackscrews that are distributed along and act against the control lip of the slice. A first carriage is moveable along a first track that is parallel to the row of jackscrews. A second carriage runs on a track on the first carriage in direction across the first track. The second carriage contains a drive motor that has a gripping device. By means of control devices and driving devices, the carriages are controlled so that the gripper in sequential order can mate with the drive shaft ends of the jackscrews for adjustment of the profile of the control lip and distance from the fixed slice lip by means of the drive motor.

Abstract: Apparatus is provided for sensing a property of a sheet (18). A sensor element (32) is adapted to be placed alongside the sheet path, and a base member (34) is adapted to be positioned on one side of the sheet and in sliding contact with one surface thereof. The sensor element is enabled to produce a sheet property sensing interaction with the sheet in a limited region of the sheet path, the interaction region being movable to any one of a plurality of sensing locations spaced across the width of the sheet. The base member has a pair of groove portions (44, 46) forming gas conducting channels with open sides exposed to the sheet surface in contact with the base member. Each of the groove portions has a part (40, 40A) extending upstream of the interaction region. The groove portions diverge from each other as they extend in a downstream (20) direction.

Abstract: A gauging apparatus for sheet materials and the like comprises a surface follower body (14,20,30) adapted to be constrained without substantial solid bodily contact and guided (e.g., by gas bearings between 32 and 36 and 38) for movement along a surface follower path that intersects the path of a traveling sheet (10) to be gauged. The body has a passage (46) adapted to carry a flow of pressurized gas to be discharged against one surface of the sheet. The discharge of the gas is effective when the body is at a predetermined distance from the surface to generate a levitating force (on 20) urging the body away from the sheet surface. Means (70,64,62) responsive to the pressure of the gas in the passage exerts on the body (at 64) a counteracting force that tends to move the body closer to the surface.

Abstract: An apparatus such as a caliper gauge can be utilized in performing a measurement, such as a thickness measurement, of a traveling sheet or the like. The apparatus comprises a surface follower body (18, 72, 74) adapted to be constrained during the measurement for movement along a surface follower path intersecting the path of the sheet (10, 80) and urged by a force toward one surface of the sheet. The body has a gas confining wall (32a, 90, 104) bounded by a uniformly distributed pressurized gas supply aperture or apertures (46, 92, 106) for pressurizing a gas bearing region (48, 108, 110) contiguous to the sheet surface with sufficient pressure against the sheet and the wall to levitate the body against the urging force. The pressurization is effected without producing substantial amounts of high velocity gas flow over the surface of the sheet within the gas bearing region.

Abstract: A method and apparatus for determining a property of a material (10) utilizes a source (28) of measuring radiation and reference radiation, a measuring information channel including a detector (30) for the measuring radiation, and a reference information channel including a detector (32) for the reference radiation. A channel-monitoring radiation is also produce. In a standardizing mode, a monitor-standardization response (M.sub.11 or R.sub.11) is derived from each of the two channels while passing monitoring radiation to both detectors and a source-standardization response (M.sub.12 or R.sub.12) is derived from each of the two channels while passing measuring radiation to the measuring detector and passing reference radiation to the reference detector. In an operating mode, an operation-monitoring response (M.sub.21 or R.sub.21) is derived from each of the two channels while passing monitoring radiation to both detectors and a material-condition response (M.sub.22 or R.sub.

Abstract: A radiant energy method and apparatus is used to determine a property such as thickness or weight per unit area of a material (14 or 40 or 170 or 238), e.g., a sheet, that is located or moving generally in a predetermined spatial relation to a first reference position (16a or 40a or 56a). A second reference position (22, 56 or 230) is defined. A sensor means (18 or 44; or 102, 112, 106 and 108; or 150, 154 and 158; or 214 and 216; or 236, 242 and 244) responds to a condition of the material. The relation of the sensor response to the material property is susceptible to change with changes in the distance relationship of the sensor means and one of the reference positions or the material. There is produced a distance response (26 or D.sub.2 (x) or 110 and 110 ' or .tau..sub.1 and .tau.'.sub.1 or D.sub.2 (.tau.) or D.sub.2 or 236, 236' or 258, 258') to changes in the distance from the sensor means to one of the reference positions. The distance response is systematically related (e.g.

Abstract: A radiation device, such as an instrument for gauging a property of moving sheet materials, has a surface including window means in the path of radiation affecting the output of a radiation detector. The radiation transmission characteristics of the portion of the radiation path including the window means are maintained substantially constant so as to reduce the probability of error in the detector output response resulting from the presence of an unpredictable amount of extraneous radiation-absorbing or scattering material in the path or at the window means. A jet of fluid, such as compressed air, is formed in a manner such that the jet is attached to the surface by implementation of the Coanda effect and directed to flow over the window means. Typically the jet is initially directed away from the portion of the surface adjoining the window means.