Accuray Inc.

Process Automation Business Inc.

Abb Industrial Systems, Inc.

Owens-corning Fiberglas Corporation

Abb Process Automation, Inc.

Steven P Sturm

Ake Arvid Hellstrom

Alan M Reid

Wim Muller

A method and apparatus are provided for sensing basis weight of a rod of material, such as tobacco, by two basis weight sensing operations which are then combined. A first sensing operation having high accuracy but slow response time is combined with a second sensing operation having low accuracy but fast response time to result in a high accuracy and fast response time output signal. The first sensing operation is performed using a low radiation beta gauge which does not require licensing or safety precautions required by currently used beta gauges. The second sensing operation is performed using a dielectric sensor. The output signals from the first and second sensing operations are time averaged and combined such that the fast response output signals from the second sensing operation are calibrated or biased using the output signals from the first sensing operation to result in a high accuracy and fast response time measurement of the basis weight for a rod of material, such as tobacco.

Measuring on-line tobacco rod basis weight using combined high

A focused light beam instrument measures characteristics of webs of sheet material. The instrument and a reference surface, a backing tile in a carousel, are on opposite sides of the web which is maintained a fixed distance from the reference surface by a Bernoulli hold down device such that variations in the gap affect the beam focus. The instrument and reference surface scan the web via a scanning frame. The instrument is calibrated-standardized in an off sheet position where a first surface, a carousel backing tile, is moved opposite to the instrument and in the plane of the web. The instrument measures the first surface and a second surface, another carousel backing tile, which is moved opposite to the instrument but spaced farther from or closer thereto than the first surface. The distance of the instrument from the web is calculated from the difference between the measurements of the first and second surfaces. The calculated distance is used to determine an operating position on an instrument response curve and the instrument is calibrated accordingly. A second or third order polynomial is fitted to the instrument response curve and differentiated at the operating point on the curve to determine the rate of change of the measurement characteristic of the instrument at that point. Gap changes and the determined rate of change of the measurement characteristics are used to compensate gap change errors in measurements made by the instrument.

On-line compensation for deflection in instruments using focused beams

Characteristics of moving webs are measured using a radiation source shutter which is rotatably movable between an opened-shutter position and a closed-shutter position and structured to permit access to the radiation source in the closed-shutter position. The source is configured to produce a fan-shaped radiation beam which passes through the web to a detector. The sizing of the fan-shaped beam and the detector together with the spacing the source and the detector are such that the beam width is substantially less than the detector while its length is greater than the detector. This novel beam shaping, detector arrangement provides composition insensitivity, increases solid beam angle and superior streak detection by aligning the beam length dimension with the direction of web movement. Alignment insensitivity is obtained by tuning the radiation beam using concentric rings or crossed strips of material which is semi-transparent to the radiation to compensate for geometric characteristics of the radiation source/beam and the detector. Air within an open portion of a measuring column extending between the radiation source and detector is conditioned and also used to condition electronics associated with the detector. The gap between the radiation source and the detector is monitored and used to compensate for variations in the measuring column air mass due to gap variations.

Methods and apparatus for measuring characteristics of moving webs

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.

Infrared analysis of paper printability

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.

Direct infrared measurement of homogenous mixtures

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. The former aspect may be employed in measuring the moisture content of heavy grade of paper having moisture weights of up to 90 grams per square meter.

Apparatus and methods employing infrared absorption means to measure the

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.

Measurement of moisture-stratified sheet material

The degree of cure of a traveling carbonaceous polymeric material (on 48), formed (at 34) from a plurality of chemical reactants (32) and subjected to a curing process (at 42 and 44) is determined by directing (with 86 and 88) into the traveling material radiations including a first infrared radiation (A1) from the group thereof adapted to selectively interact with molecular resonance vibrations at frequencies that are characteristic of respective terminal functional groups of atoms involved in reactions that take place in the material during the curing process. Also directed into the material is a second infrared radiation that is either of the kind (R) that does not exhibit substantial selective interaction with molecular resonance vibrations in the material or of the kind (A2) that is adapted to selectively interact with molecular resonance vibrations at a frequency that is characteristic of groups of atoms forming the backbones of the polymeric molecules in the material. Received (at 102) from the traveling material are radiations (148) that have interacted with the material. Produced (at 116, 118 and 122) from the received radiations are first and second responses to the first and second radiations. Produced (at 122) is a third response that is a function of the mass of the polymeric material interacting with the radiations. Produced (at 122) from the first, second and third responses is an output response (140, 82) that is correlated with the degree of cure effected by the curing process.

Methods and apparatus for measuring and controlling curing of polymeric

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.

Measuring the percentage or fractional moisture content of paper having

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.22) is derived from each of the two channels while directing source radiation into the material and passing to the respective measuring and reference detectors measuring and reference radiation that has interacted with the material. By responding to the monitor-standardization responses, the source-standardization responses, the operation-monitoring responses and the material-condition responses, there is produced a material property response (at 164 or 166) that is effectively standardized and substantially independent of gain changes occurring in either one or both of the measuring and reference information channels. The example shows the measurement of moisture content in a traveling sheet of paper with infrared radiation at 1.4.mu., 1.8.mu. and 1.9.mu..

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Columbus, OH, United States of America

Steven P Sturm