Abstract: A method of level finding includes providing characteristics of a shape of a transmitted pulse in time domain launched onto a waveguide into a tank having at least one material therein, physical properties of the waveguide and real and imaginary dielectric characteristics of the material at a frequency of the pulse. A level finding algorithm having a coarse search and a fine search is implemented, where the coarse search minimizes a prediction error between an echo signal (echo curve y(k)) and a sampled pulse model echo p(k) to obtain an objective function J(k) in a vicinity of a minimum prediction error (k*). The fine search calculates at least one minimum or maximum using J(k) in the vicinity of k*. The minimum or the maximum corresponds to a level of the material or an interface involving the material.

Abstract: A method of pulsed radar interface determination for a first and second material in a tank. An interface level determination model is provided including a transfer function that utilizes refractive indices for the materials and thickness of the second material. At least one actual radar pulse is transmitted into the tank and a resulting echo curve portion including a measured interface pulse(s) around the interface location is measured. The interface model is simulated with a reference pulse and an initial thickness value to generate an initial model generated interface pulse (initial MGIP). The measured interface pulse is compared to the initial MGIP pulse point-by-point to determine residuals. If the residuals sum >a predetermined threshold, the comparing is repeated with an updated interface model generated with an updated thickness value that provides an updated MGIP pulse. When the sum of residuals is ?predetermined threshold, the thickness is determined.

Abstract: A method of modeling a pulsed radar gauge (PRG) that includes a transceiver coupled by a process connection to a probe installed on a tank having at least one product material therein. A mathematical model is provided that includes (i) dielectric properties and dimensions of materials used in the process connection, (ii) at least one tank dimension, (iii) dielectric characteristics of the product material, and (iv) a probe length. Using a processor implementing a stored echo prediction algorithm that utilizes the mathematical model inputting pulse characteristics including a shape of an input radar pulse launched by a transmitter of the transceiver onto the probe into the mathematical model, and generating a predicted echo curve from the mathematical model.

Abstract: Continuous on-line thin film measurements employ a sensor having a spectrometer for interferometric measurements and a stack of single channel detectors for adsorption measurements. The stack is separated from the spectrometer, which analyzes radiation that emerges (transmitted pass or reflected from) the film, whereas the stack analyzes radiation that has passed through the film multiple times. The spectrometer is (i) positioned directly opposite the source of radiation so that it detects transmitted radiation or (ii) disposed on the same side of the film as is the source of radiation so that the spectrometer detects radiation that is specularly reflected from the film. The sensor includes a broadband radiation source emitting visible to far infrared light which propagates through a measurement cell defined by reflective surfaces exhibiting Lambertian-type scattering. The sensor is capable of measuring thin plastic films with thicknesses down to 1 micron or less.

Abstract: A coupling device for impedance matching a probe of a guided wave radar (GWR) system. A feed-through is for connecting to a coaxial cable or other transmission line connector that includes an inner conductor which connects to an output of a transceiver and an outer conductor that connects to an outer metal sleeve. A subwavelength coaxial transmission line (CTL) having a length from ?/5 to ?/2 is coupled to the feed-through including an inner conductor connected to the inner conductor of the feed-through and an outer conductor connected to the outer metal sleeve. A mode converter (MC) having a plurality of metal fingers (7) of length 2?± twenty percent is connected to the outer conductor of the subwavelength CTL, where the MC includes a dielectric coating on its inner conductor connected to the inner conductor of the subwavelength CTL.

Abstract: A coupling device for coupling a threaded feed-through of a process connection to provide a launcher for a non-metallic storage tank. The storage tank includes a tank aperture in its top surface. The coupling device includes a foil nozzle including an inner upper metal foil surface that includes a threaded aperture for securing the feed-through thereto, and a first and second lower metal foil surface on respective sides of the upper metal foil surface. The foil nozzle also includes a first and a second foil level transition region disposed between the respective sides of the inner upper metal foil surface and the first and second lower metal foil surface. The foil nozzle can be configured in a cylindrical, horn, or a corrugated horn shape.

Abstract: A coaxial probe for a time-domain reflectometry (TDR) fill-level measuring system includes an outer electrically conductive tube (outer tube), an inner electrically conductive rod (inner rod) within the outer tube on at least one end, and at least one tensioning device (tensioning device). The tensioning device includes a tensioner body between the inner rod and outer tube for stretching the inner rod in a length direction relative to the outer tube to tension the inner rod. The tensioning device is placed at at least one of an end of a lower probe portion and an end of an upper probe portion of the coaxial probe.

Abstract: A coaxial feed-through device (feed-through) for coupling a received process connection to a storage tank (tank) including an inner electrical conductor (probe), an outer electrical conductor; and a dielectric sleeve disposed between the probe and the outer electrical conductor. The dielectric sleeve is configured to provide an upper coaxial transmission line segment (upper CTL segment) providing a substantially 50 ohm impedance and a lower coaxial transmission line segment (lower CTL segment) which includes one or more sub-segments having an impedance that is at least forty (40%) percent higher as compared to the substantially 50 ohm impedance.

Abstract: An apparatus includes a sensing head. The sensing head is configured to transmit a pulse through a first probe of at least a first probe and a second probe. The sensing head is also configured to receive the pulse from the first probe and identify that the pulse was received through the first probe. The sensing head is further configured to determine a depth of a material in contact with the first probe in response to receiving the pulse.

Abstract: Continuous on-line thin film measurements employ a sensor having a spectrometer for interferometric measurements and a stack of single channel detectors for adsorption measurements. The stack is separated from the spectrometer, which analyzes radiation that emerges (transmitted pass or reflected from) the film, whereas the stack analyzes radiation that has passed through the film multiple times. The spectrometer is (i) positioned directly opposite the source of radiation so that it detects transmitted radiation or (ii) disposed on the same side of the film as is the source of radiation so that the spectrometer detects radiation that is specularly reflected from the film. The sensor includes a broadband radiation source emitting visible to far infrared light which propagates through a measurement cell defined by reflective surfaces exhibiting Lambertian-type scattering. The sensor is capable of measuring thin plastic films with thicknesses down to 1 micron or less.

Abstract: A method of pulsed radar interface determination for a first and second material in a tank. An interface level determination model is provided including a transfer function that utilizes refractive indices for the materials and thickness of the second material. At least one actual radar pulse is transmitted into the tank and a resulting echo curve portion including a measured interface pulse(s) around the interface location is measured. The interface model is simulated with a reference pulse and an initial thickness value to generate an initial model generated interface pulse (initial MGIP). The measured interface pulse is compared to the initial MGIP pulse point-by-point to determine residuals. If the residuals sum >a predetermined threshold, the comparing is repeated with an updated interface model generated with an updated thickness value that provides an updated MGIP pulse. When the sum of residuals is ?predetermined threshold, the thickness is determined.

Abstract: A method of modeling a pulsed radar gauge (PRG) that includes a transceiver coupled by a process connection to a probe installed on a tank having at least one product material therein. A mathematical model is provided that includes (i) dielectric properties and dimensions of materials used in the process connection, (ii) at least one tank dimension, (iii) dielectric characteristics of the product material, and (iv) a probe length. Using a processor implementing a stored echo prediction algorithm that utilizes the mathematical model inputting pulse characteristics including a shape of an input radar pulse launched by a transmitter of the transceiver onto the probe into the mathematical model, and generating a predicted echo curve from the mathematical model.

Abstract: A method of level finding includes providing characteristics of a shape of a transmitted pulse in time domain launched onto a waveguide into a tank having at least one material therein, physical properties of the waveguide and real and imaginary dielectric characteristics of the material at a frequency of the pulse. A level finding algorithm having a coarse search and a fine search is implemented, where the coarse search minimizes a prediction error between an echo signal (echo curve y(k)) and a sampled pulse model echo p(k) to obtain an objective function J(k) in a vicinity of a minimum prediction error (k*). The fine search calculates at least one minimum or maximum using J(k) in the vicinity of k*. The minimum or the maximum corresponds to a level of the material or an interface involving the material.

Abstract: A method of pulsed radar level sensing. First level scanning performed with first transmitted radar pulses launched by a probe into a tank having a first pulse width, wherein the first level scanning is over a first scan distance. First echoes generated responsive to the first pulses are analyzed to determine an approximate level of a material in the tank. Second level scanning with second transmitted radar pulses are launched by the probe into the tank having a second pulse width, with a measurement window<the first scan distance that includes the approximate level. The second pulse width<the first pulse width. Second echoes generated responsive to the second pulses are analyzed to determine a revised higher resolution material level measurement.

Abstract: Scanning sensor for measuring properties of continuous flat sheet, that is moving in the machine direction, employs an IR radiation source for directing a beam of incident IR radiation that impinges the sheet. The IR source has elongated lamp filament that generates IR radiation and the corresponding spot size formed on the sheet has elongated dimensions with its long axis being aligned with the machine direction. Aligned with the MD maximizes sensor spatial resolution in the cross direction. The sensor can employ a receiver having rectangular geometry with its long axis being aligned also in the MD. Scanning sensor can operate in the reflective, transmissive, or offset transmission mode to monitor characteristics of flat sheets, particularly of paper or plastic products.

Abstract: A coaxial feed-through device (feed-through) for coupling a received process connection to a storage tank (tank) including an inner electrical conductor (probe), an outer electrical conductor; and a dielectric sleeve disposed between the probe and the outer electrical conductor. The dielectric sleeve is configured to provide an upper coaxial transmission line segment (upper CTL segment) providing a substantially 50 ohm impedance and a lower coaxial transmission line segment (lower CTL segment) which includes one or more sub-segments having an impedance that is at least forty (40%) percent higher as compared to the substantially 50 ohm impedance.

Abstract: A coupling device for coupling a threaded feed-through of a process connection to provide a launcher for a non-metallic storage tank. The storage tank includes a tank aperture in its top surface. The coupling device includes a foil nozzle including an inner upper metal foil surface that includes a threaded aperture for securing the feed-through thereto, and a first and second lower metal foil surface on respective sides of the upper metal foil surface. The foil nozzle also includes a first and a second foil level transition region disposed between the respective sides of the inner upper metal foil surface and the first and second lower metal foil surface. The foil nozzle can be configured in a cylindrical, horn, or a corrugated horn shape.

Abstract: Scanning sensor for measuring properties of continuous flat sheet, that is moving in the machine direction, employs an IR radiation source for directing a beam of incident IR radiation that impinges the sheet. The IR source has elongated lamp filament that generates IR radiation and the corresponding spot size formed on the sheet has elongated dimensions with its long axis being aligned with the machine direction. Aligned with the MD maximizes sensor spatial resolution in the cross direction. The sensor can employ a receiver having rectangular geometry with its long axis being aligned also in the MD. Scanning sensor can operate in the reflective, transmissive, or offset transmission mode to monitor characteristics of flat sheets, particularly of paper or plastic products.

Abstract: A coupling device for impedance matching a probe of a guided wave radar (GWR) system. A feed-through is for connecting to a coaxial cable or other transmission line connector that includes an inner conductor which connects to an output of a transceiver and an outer conductor that connects to an outer metal sleeve. A subwavelength coaxial transmission line (CTL) having a length from ?/5 to ?/2 is coupled to the feed-through including an inner conductor connected to the inner conductor of the feed-through and an outer conductor connected to the outer metal sleeve. A mode converter (MC) having a plurality of metal fingers (7) of length 2?±twenty percent is connected to the outer conductor of the subwavelength CTL, where the MC includes a dielectric coating on its inner conductor connected to the inner conductor of the subwavelength CTL.

Abstract: An apparatus for incorporation into time-domain spectroscopy systems that creates a continuous reference whereby a sample pulses' phase and amplitude can be tracked and corrected employs a beam splitter to generate sample and reference pulses. A detector is positioned for receiving the reference radiation pulses that do not interact with the sample. The same detector is also positioned for receiving the sample radiation pulses that emerge from the sample. The apparatus can be readily implemented by being configured between the emitter and detector of a terahertz time-domain spectrometer. The reference pulse is used to trace the changes in time and amplitude of the sample pulse. Since any changes in the reference pulse will most likely manifest in the sample pulse, the reference pulse is monitored and used to correct the sample pulse and thereby reduce the effects of jitter.