Abstract: A spectroscopic method and spectroscopy system therefrom for analyzing samples. A sample includes a first chemical component that has a characteristic first absorption peak is provided. The sample is irradiated in a measurement waveband proximate to the first absorption peak, and at a first and a second reference waveband where the first chemical component lacks characteristic absorption features. Reflected or transmitted detection data is obtained including a measured power proximate to the first absorption peak and first and second reference powers at the reference wavebands. A plurality of different waveband ratios are evaluated using pairs of detection data to generate a plurality of measured waveband ratio values.

Abstract: An apparatus (200) for determining fiber orientation parameters of a sheet of material during a production process includes a polarized radiation generating system (201, 202) operable for providing polarized radiation having a frequency of at least 1×108 Hz. The radiation is aligned to be incident on a sheet of material to be characterized (203). A polarimeter (204, 205) is aligned to receive the radiation transmitted by the sheet of material (203). A photodetector (206) is provided for measuring radiation received after polarization processing by the polarimeter. A processor (207) is coupled to the photodetector (206) for calculating Stokes parameters of the moving sheet (203) based upon intensities of the radiation received and determines at least one parameter relating to fiber orientation of the moving sheet based upon the Stokes parameters.

Abstract: A spectroscopic method and spectroscopy system therefrom for analyzing samples. A sample includes a first chemical component that has a characteristic first absorption peak is provided. The sample is irradiated in a measurement waveband proximate to the first absorption peak, and at a first and a second reference waveband where the first chemical component lacks characteristic absorption features. Reflected or transmitted detection data is obtained including a measured power proximate to the first absorption peak and first and second reference powers at the reference wavebands. A plurality of different waveband ratios are evaluated using pairs of detection data to generate a plurality of measured waveband ratio values.

Abstract: A system and method of monitoring with temperature stabilization. The system can include a housing operably connected to a fiber optic cable that provides a light wave thereto, a relay optic for receiving the light wave and being positioned in the housing, a radiation device for processing or producing radiation in the frequency range of 10 GHz to 100 THz from the light wave and being positioned in the housing, a temperature sensor in thermal communication with the housing, and a thermal management device in thermal communication with the housing where the thermal management device adjusts a temperature within the housing based on temperature conditions measured by the temperature sensor. Other embodiments are disclosed.

Abstract: A material measurement system (500) includes a THz generator including at least one laser source (111) for emitting optical pulses, the optical pulses coupled to a THz emitter (51) operable for emitting pulsed THz radiation at a sample location on material while being processed (14) by a manufacturing system. A receiver (52) is operable to receive the optical pulses and to detect reflected or transmitted THz radiation from the sample location (14) synchronously with the optical pulses and provide electrical detection signals. Synchronizing optics (112, 113, 114) is operable to receive the optical pulses from said laser and provide the optical pulses to both the receiver (52) and the THz emitter (51).

Abstract: A scanning system includes a cable take-up mechanism that uses a series of pulleys that determine the bend diameters of a scanning system. The mechanism is particularly suited for a spectrometric, e.g., infrared, scanning system where moving scanner or sensor head essentially houses only the optical elements while essentially of all the other electronic and optical components associated with the measurement are housed in an easily accessible compartment that is remote from the moving scanner head. Light is transmitted through optical fiber cables. The cable take-up mechanism maintains the fiber optic cable at essentially constant total bend length and bend diameter thereby minimizing any dynamic changes to spectral bend losses as the optical head is scanned. The light weight construction of the sensor head further reduces vibrations associated with the moving scanner head.

Abstract: A material measurement system (500) includes a THz generator including at least one laser source (111) for emitting optical pulses, the optical pulses coupled to a THz emitter (51) operable for emitting pulsed THz radiation at a sample location on material while being processed (14) by a manufacturing system. A receiver (52) is operable to receive the optical pulses and to detect reflected or transmitted THz radiation from the sample location (14) synchronously with the optical pulses and provide electrical detection signals. Synchronizing optics (112, 113, 114) is operable to receive the optical pulses from said laser and provide the optical pulses to both the receiver (52) and the THz emitter (51).

Abstract: An apparatus (200) for determining fiber orientation parameters of a sheet of material during a production process includes a polarized radiation generating system (201, 202) operable for providing polarized radiation having a frequency of at least 1×108 Hz. The radiation is aligned to be incident on a sheet of material to be characterized (203). A polarimeter (204, 205) is aligned to receive the radiation transmitted by the sheet of material (203). A photodetector (206) is provided for measuring radiation received after polarization processing by the polarimeter. A processor (207) is coupled to the photodetector (206) for calculating Stokes parameters of the moving sheet (203) based upon intensities of the radiation received and determines at least one parameter relating to fiber orientation of the moving sheet based upon the Stokes parameters.

Abstract: A system and method of monitoring with temperature stabilization. The system can include a housing operably connected to a fiber optic cable that provides a light wave thereto, a relay optic for receiving the light wave and being positioned in the housing, a radiation device for processing or producing radiation in the frequency range of 10 GHz to 100 THz from the light wave and being positioned in the housing, a temperature sensor in thermal communication with the housing, and a thermal management device in thermal communication with the housing where the thermal management device adjusts a temperature within the housing based on temperature conditions measured by the temperature sensor. Other embodiments are disclosed.

Abstract: Infrared spectroscopy techniques are employed to measure (i) the moisture level in both the sheet of wet stock and the papermaking machine clothing on which the sheet is supported and (ii) the moisture level in the clothing alone as a separate layer of material. Differential measurement thus yields the moisture content of the sheet of wet stock alone. Changes in the moisture level in the clothing at the press section can be correlated with corresponding changes in the quality or physical property of the paper produced. Both fixed point and scanning IR sensors are strategically positioned in the press section to generate machine direction and/or cross machine direction water profiles for process control.

Abstract: Temperature measurements of sheet material such as paper can be obtained directly from an analysis of the absorption spectrum of water in the infrared region. The technique is based in part on the recognition that the central wavelength position of a selected moisture peak is dependent upon the sheet temperature; the wavelength position also has a known temperature sensitivity. Thus, once the wavelength position of this moisture peak is ascertained, the moisture temperature of the product being monitored can be calculated. The position of the moisture peak is preferably obtained from the derivative of the peak. By measuring the size of the infrared absorption and the wavelength position of the absorption peak, both the moisture content and the moisture temperature of the sheet material can be determined. The data is used for process control. Tunable laser diodes are particularly suited as the source of infrared radiation for the temperature sensors.

Abstract: A measurement system for measuring a degree of moisture stratification in a flat sheet product, such as paper, board or other materials. The system uses a combination of a reflection gauge and a transmission gauge to provide output signals indicative of surface moisture of a first side and of moisture in the body of the flat sheet product. The output signals are processed by a controller or computer to provide a measurement of the moisture stratification. An additional reflection gauge and an additional transmission gauge can also be used to provide additional output signals indicative of surface moisture of a second side of the flat sheet product and of moisture in the body. Narrow band radiation is used with modulation to distinguish from ambient radiation as well as radiation incident on the opposite side.

Abstract: A spectroscopic sensor for measuring flat sheet product is disclosed. The disclosed sensor uses a combination of spectrometers and single-channel detectors and filters together with a broadband source of illumination to optimally measure multiple properties of a flat sheet product. A spectrometer is used to measure over a spectral range where an easily configurable set of wavelength channels is needed and where the signal-to-noise ratios and spectral resolutions of the channels are consistent with the spectral range and number of pixels of the spectrometer; while one or more single channel detector and filter combinations are used to measure, with high signal-to-noise ratio, at specific wavelengths within or outside the spectral range of the spectrometer(s).

Abstract: A sensor for measuring at least selected component in a composition can include: (a) a broadband light source, (b) an acousto-optic tunable filter (AOTF), (c) means for generating a beam of light from the light source and directing the beam of light at the AOTF wherein the AOTF is tuned to pass detection light having a desired wavelength range to detect the presence of the at least one component in the composition, (d) means for directing the detection light of known wavelength to the composition, (e) detection means for receiving light that emerges from the composition, and (f) a control signal generator configured to provide the AOTF with at least one desired wavelength range that is characteristic of the least one component in the composition. As an example, the sensor can be used to measure the thickness of optically transparent films.

Abstract: A compact, long lasting sensor for measuring components such as moisture in moving sheets including paper in a papermaking apparatus employs light sources that produce radiation within defined wavelength regions of interest and the light sources are modulated at high frequencies using non-mechanical techniques. A single detector with various radiation sources can measure at all frequencies while keeping information separated. Superluminescent light emitting diode or laser diode light sources can be directly electrically modulates for improved noise rejection. These higher power and bright light sources afford excellent fiber optic launch efficiency and permits the sensor to be scanned at much faster rates over the paper being monitored.

Abstract: A spectroscopic sensor for measuring flat sheet product is disclosed. The disclosed sensor uses a combination of spectrometers and single-channel detectors and filters together with a broadband source of illumination to optimally measure multiple properties of a flat sheet product. A spectrometer is used to measure over a spectral range where an easily configurable set of wavelength channels is needed and where the signal-to-noise ratios and spectral resolutions of the channels are consistent with the spectral range and number of pixels of the spectrometer; while one or more single channel detector and filter combinations are used to measure, with high signal-to-noise ratio, at specific wavelengths within or outside the spectral range of the spectrometer(s).

Abstract: Techniques for non-contacting thickness or caliper measurements of moving webs or sheets employ a sensor device that includes a first sensor head and a second sensor head that are spaced apart to define a path through which the moving web travels. The sensor device projects a laser generated, multiple points pattern onto the upper surface of the moving web. Pattern recognition algorithm analysis of the pattern identifies the orientation, e.g., tilt, of the moving web. The device further measures the film tilt, the distance between the first sensor head and the first web surface, the distance between the second sensor head and the second web surface, and the distance between the two sensor heads to provide a highly accurate on-line thickness measurement of the moving web.