Abstract: An air bearing gauge 10 is characterized by a flat land 30, instead of the prior art's "knife-edge" 30', so as to provide an area 32 over web 12 through which pressurized gas flows in escaping from the gas supply means 16 and the gas bearing region 24. The land 30 provides an upward scaling of the readings obtained on-line, which can correlate the reading to standard TAPPI caliper gauge measurements of sheets as are obtained off-line, in the laboratory.

Abstract: A pressure sensor 10 is made up of silicon diaphragm 12 sandwiched between two housing members 20 and 22 with external conduits 24, 26. The diaphragm 12 has a central rigid disc 14 which moves axially like a piston, a peripheral rim 16 and an integral web 18. The rim 16 is undercut to provide recesses 46 and 48 (FIG. 1 ) or recess 50 (FIG. 6) which reduces the net reactive forces tending to separate the joints 42 and 44 between rim 16 and the housing parts 20, 22. Overpressure stop surfaces 28 and 30 on the inside of the housing cavity form capacitor gaps with the opposite flat sides of rigid disc 14 for signal output to readout circuitry 40 in the rated range. Configurations for gage pressure and absolute pressure are disclosed, as well as a system of isolation from corrosive process environments.

Abstract: A standard control signal for a web forming machine is temporarily interrupted and replaced by a perturbing signal or signgals which are applied to one, a grouping, or all of a series of actuation cells of the web forming machine. One or more actuation cells are driven with an alternating perturbing signal(s) which generate a corresponding action in the actuation cell(s). The perturbing signal(s) alternates from a neutral position of the cell and is selected to minimize means effects over any given period of time. The effects of the alternating signal(s) on the web appear within the area of the web which is affected by the actuation cell(s) such that the mapping and the response of the actuation cell(s) can be determined by monitoring that poriton of the web which is formed while the alternating signal(s) is applied to the actuation cell(s).

Abstract: A method and apparatus are disclosed wherein a plurality of basis weight sensors are interleaved with one or more processing stations used to conjoin or apply one or more layers to a base substrate to form a multilayer product such that a sensor is located on the input and output sides of each processing station. Each of the sensors can be calibrated with a plurality of product calibrations such that multiple output signals corresponding to multiple products can be generated simultaneously by the sensors. Each of the sensors is calibrated with product calibrations corresponding to the product or intermediate stage of the product which it monitors, the layer applied by the processing station preceding it, if any, and the layer applied by the processing station succeeding it, if any.

Abstract: Method and apparatus for measurement and control of an industrial process by detecting the average transmittance of a radiation beam which passes through the process material. A radiation source (28) having an intensity I.sub.o is positioned on one side of the material to be measured and a suitable radiation detector (32) is positioned on the other side. The transmitted radiation intensity, I, is measured by the sensor. An index Z commensurate with the degree of nonuniformity of the variable in the material is determined, and a process signal is generated from a quantitative relationship among I, I.sub.o, and the index Z. In a first embodiment implementedd in a system for measurement and control of the basis weight of paper in a paper production process, the index Z is indicative of the nonuniformity of the material mass distribution in the sheet and is determined by measurements with a separate formation gauge operating on-line with, but independently of, the basis weight sensor.

Abstract: An apparatus 10 is provided for supplying a high-velocity flow of temperature regulated air 5 to the calender roll 90 of a paper making machine. Ambient air 1 is received into the plenum chamber 20 and distributed therefrom through a longitudinally elongated conduit means 30 which has an inlet 32 opening directly into the plenum chamber 20 and an outlet opening 36 along the other end thereof and defining therebetween a flow passageway 34. The outlet opening 36 is adapted to direct the air flow passing through the flow passageway 34 along the calender roll 90 in counter direction to the rotation of the calender roll 90. A series of spiral wound heating element coils 40 are disposed within the conduit means 30 at longitudinally spaced intervals along the length thereof to heat the air to a desired temperature by selectively powering the heating element coils 40.

Abstract: A two-speed stepper actuator (10) for rotationally driving a power nut (24) to adjust a slice lip spindle (20) linearly. A clamp for power nut (24) includes a bushing plate (32) driven by drive solenoid (D) which is mounted for rotation relative to power nut (24). A lever (40) is pivotally mounted on the bushing plate (32) and includes an eccentric locking cam surface (50) shaped for selective clearance of nut (24) when in the center or number 2 position and clamping engagement of nut (24) when in the opposite extreme 1 and 3 positions. A first amount of rotation of the lever (40) about its pivotal mounting (48) on said bushing plate (32) engages and locks lever end cam surface (50) against nut (24) and a second and additional rotation of the lever (40) then drives the nut (24). Three position solenoids (L) and (D) drive the bushing plate (32) and lever (40) independently and at different speeds due to an accommodation by spring (36) on pusher rod (34) of solenoid (L).

Abstract: The printability of paper coated with kaolinite clay is dependent upon the flatness of kaolinite alumino-silicate clay platelets on the surface thereof. The flatness is determined by calculating the ratio of two infrared absorption bands from two specific types of structural hydroxyls characteristic of kaolinite clay platelet crystals.

Abstract: A light source module for use with a multi-camera array in a video surface inspection system includes a first light emitter which extends lengthwise across the entire width of a sheet to be inspected. Light from the first light emitter, which preferably comprises one or more fluorescent lamps, is received by a light guide and carried by the guide to uniformly illuminate a band extending entirely across the width of the moving sheet. The light guide comprises a transparent thermoplastic such that the light receiving end of the guide can be bent to define a plurality of sections which can be axially aligned with a corresponding plurality of fluorescent lamps. The fluorescent lamps may be powered by individual inverter ballasts which may be driven inturn by one or more variable dc power supplied to control the intensity of light emitted by the lamps.

Abstract: Apparatus for inspecting sheet material having known characteristics is disclosed. The apparatus comprises means for providing a plurality of pixel signals each having a magnitude representing the intensity of electromagnetic radiation received from a corresponding point on the sheet material. The apparatus also comprises signal processing means for comparing the magnitude of each one of the pixel signals to a corresponding reference range defined by the known characteristics of the sheet material and generating a characteristic signal. The characteristic signal includes an event signal for each of the magnitudes falling outside of the corresponding reference range and a data signal for each of the magnitudes falling within the range, wherein the data signal represents the magnitude of the pixel signal. The signal processing means also generates an address signal representing the point on the sheet material at which the characteristic signal is generated.

Abstract: Apparatus (10) and methods for measuring dark and bright reflectances of translucent sheet material (2) are disclosed. The apparatus (10) comprises first optical means for illuminating one side of the sheet material (2) with a source of electromagnetic radiation. A portion of the radiation is transmitted through the sheet material (2) and another portion of the radiation is reflected by the sheet material. The apparatus (10) also comprises optical gating means (30) that is positioned adjacent the other side of the sheet material (2) in a fixed position relative to the first optical means. The optical gating means (30) absorbs substantially all of the transmitted portion of the radiation when switched to a dark state and reflects substantially all of the transmitted portion of the radiation back through the sheet material (2) when switched to a bright state.

Abstract: A body (12) containing a substantially cylindrical bore (14) as fluidly connected in a straight pipe run, the bore having opposed relatively upper and relatively lower wall portions (94,96) and opposed side wall portions. A pair of substantially solid wedge members (30,32) are detachably secured to the side wall portions and project toward the bore axis (34), partially blocking the flow of fluid through the bore to produce a differential pressure upstream and downstream of the wedge members. Sensors (64,66,68,70) are provided upstream and downstream of the wedge members, through the side walls of the bore, to obtain differential pressure measurements from which the fluid flow rate can be computed.

Abstract: A two-speed stepper actuator unit for use in paper machine headbox slice lip control has a spindle 16 driven by a power nut 24. A lever clamp 32 has legs 34 and 36 selectively clamped together around nut 24 by means of a cam action locking plate 40 driven by solenoid 48. The longer leg 36 of clamp 32 has a cam follower which rotationally drives nut 24 through the lever 36 in response to the shape of a cam plate 50 which translates in the housing 12 on antifriction rollers 66 when drive solenoid 54 is actuated. The cam surface 60 guides the lever 36 in either of two speed modes depending on whether spring biased roller follower 52 is on cams surface portion 62 or 64.

Abstract: A paper machine headbox slice lip rotector system which permits limited incremental movement up or down by means of a pivoting lever arm 32 with lock bolt end portions 36 and 38 moving in adjacent protectors' adjustable keeper recesses 40. The recesses 40 are defined by stop nuts 42 on a threaded body fixed to the adjustable spindles 20. The lever arm 32 is pivotally mounted on the body for permitting up and down movement a distance which is the average of the distance defined by the keeper recesses 40 of the adjacent protectors. This prevents the prior art problem of a protector being "locked" between adjacent protectors.

Abstract: A sheet inspection station including pneumatic means for guiding the sheet past one or more measurement sensors in non-contacting fashion, thus eliminating measurement error resulting from fiber/dust buildup associated with friction between the sheet and conventional guide rails. Air is directed from components, that extend from a sensor surface, onto the sheet surface.

Abstract: Apparatus and associated methods for measuring the polymer content of a mixture having polymer and cellulose components. Infrared absorption means are employed to derive a measurement of that fraction of the combined weights of polymer and cellulose components which is accounted for by the polymer.

Abstract: A circuit and method for converting a binary number having a plurarity of bits, D.sub.o to D.sub.n, to a signal having a proportionally equivalent characteristic. The circuit comprises a parallel input for receiving each bit, D.sub.o to D.sub.n, of the binary number and means for generating a plurarity of wavetrains, W.sub.o to W.sub.n, having frequencies decreasing by powers of two from the least significant wavetrain, W.sub.o, to the most significant wavetrain, W.sub.n. Each wavetrain comprises pulses having a pulse width equal to the inverse of twice the frequence of the least significant wavetrain, W.sub.o, so that the duty cycle of each of the wavetrains is proportional to the corresponding frequency thereof. The pulses of each of the wavetrains are not overlapping with the pulses of the other wavetrains. The circuit also comprises logic means, connected to the input and the generating means, for logically multiplying each wavetrain taken in an order from the least significant to the most significant, W.

Abstract: Apparatus and methods for use in measuring the moisture content of heavy-grade sheets of paper during their continuous manufacture. In one aspect, means employing infrared absorption techniques for determining the fiber weight per unit area of a sheet having a fiber weight of up to 1100 grams per square meter are provided. In another aspect, means employing infrared absorption techniques including the use of two moisture absorption bands and associated moisture reference bands for calculating the average temperature of the sheet are provided. The latter aspect may be used to produce an indication of moisture weight per unit area, wherein the indication is substantially independent on changes in the average temperature, and enables accurate measurement of the moisture weight per unit area of heavy grades of paper having moisture weights of up to 450 grams per square meter.

Abstract: A beam of X rays is directed into a traveling product such as paper having a constituent such as ash made up of components such as clay, chalk and titanium dioxide.X rays from the product may produce signal channel responses that are the same to one component but different to another component, and a resultant response indicative of the content of the constituent or component.The X rays from the product may produce a response to a detected spectrum wherein the intensities of the rays are so distributed as a function of energy that the average effective absorption coefficients for the components are substantially equalized, so that the response will be indicative of the constituent and comparatively unaffected by the relative amounts of the components.

Abstract: An apparatus for measuring the thickness of a sheet of metal by irradiating the sheet with x-rays. The intensity of the initial x-rays, the transmitted x-rays, and the backscattered x-rays are detected and the detector signals are processed to produce a signal representing the thickness of the metal sheet.