Abstract: A densitometer using a microwave comprises a microwave detection section, a phase detection section, and a density calculation section. The microwave detection section picks up a first microwave receiving signal by transmitting and receiving a microwave of a frequency band of 1.4 --GHz-- to 1.75 --GHz-- to/from a reference fluid, and a second microwave receiving signal by transmitting and receiving a microwave of a frequency band of 1.4 --GHz-- to 1.75 --GHz-- to/from a measuring fluid. The phase detection section obtains a phase difference between the first microwave receiving signal and the second microwave receiving signal. The density calculation section calculates the density of measuring fluid based on the phase difference obtained by the phase detection section.

Abstract: The invention is an apparatus for measuring the attenuation of electromagnetic radiation between cells of honeycomb core. In detail, the apparatus includes at least two antennas in a spaced relationship. A positioning system is used for positioning the at least two antennas within individual cells of the core. An analysis system is coupled to the antennas for measuring the attenuation of the radiated electromagnetic radiation between one of the antennas operating in a radiating mode and a second operating in a receiving mode and providing a graphical representation of the attenuation as a function of frequency, depth, length or width.

Abstract: An apparatus for detecting the accumulation of particulate material on a filter medium formed of dielectric material and disposed in a chamber is provided. The apparatus is operable for generating and transmitting an RF signal through the filter medium and for monitoring the transmission loss of the signal through at least a portion of the filter medium so as to provide an indication of the content of particulate material accumulated on the filter medium. The apparatus includes an input antenna for transmitting the signal and having at least one antenna element extending longitudinally of the chamber and disposed within the filter medium; and an output antenna for receiving the signal transmitted by the input antenna and having at least one antenna element extending longitudinally of the chamber and disposed within the medium in parallel, spaced apart, axially overlapping relation with respect to the input antenna element.

Abstract: A tire cure control system and method characterized by a computer-based data acquisition and process control unit that uses non-invasive, direct cure measurements to adjust the length of cure so that all cured articles such as tires will be cured to the same extent in the minimum amount of time, thereby to maximize production while providing uniformly cured products. The unit generally includes at least one microwave probe, although preferably multiple microwave probes, placed in the mold and a processor to process probe data and to initiate a control action principally initiating a mold opening sequence at the optimal time. Initiation of the mold opening sequence at least in part is based upon a measurement of the time rate of change of the attenuation of microwave energy caused by the curing rubber compound in the mold.

Abstract: The present invention provides an apparatus and method for the measurement of, for example, the moisture in a material or, more generally, for the measurement of any material parameter which may be inferred by measuring the electromagnetic properties of the material under investigation. The electromagnetic properties of use in the present invention are complex electrical permittivity or the magnetic permeability of the material. The meter apparatus of the present invention comprises a controllable source of electromagnetic energy having stable selectable frequency. The controllable source of electromagnetic energy is coupled to a material measurement chamber by means of probes, loops, antennas, apertures or other structures so as to establish an electromagnetic wave inside the measurement chamber thereby causing the wave to interact with the material contained in the chamber.

Abstract: For measuring an interface between two fluids, a device (10, 75, 90) having n electrical circuit comprising transmitting means, a detector, a first antenna (14, 18, 78, 82, 92) and a second electrically grounded antenna (15, 18, 79, 83, 93), the transmitting means being arranged to transmit electrical impulses between the first and second antennas through one of the two fluids so as to be absorbed thereby, and the detector being arranged to detect a change in either an impedance or a rate of absorption of energy which occurs at the interface. The device includes a housing (11, 91) for placing in the fluids so as to contact the interface along a periphery of the housing towards a first end thereof, the first antenna (14, 18, 78, 82, 92) projects from the housing at said periphery, and the electrical circuit includes a coupling means (28) for coupling thereto a remote monitoring means whereby the interface may be measured remotely.

Abstract: This application describes a method of testing for manufacturing faults and quality of unpopulated or inactive populated electronic printed circuit boards (PCB). This method can be used to develop a new contactless test system (CTS). An electromagnetic field is generated by an energizing plate connected to an AC signal. When a board under test (BUT) is placed within the electromagnetic field, perturbation of the original field by conducting elements on the BUT is solely a function of the geometrical layout of the conducting elements on the BUT. Therefore, measurement of the perturbed electromagnetic field produces a characteristic pattern for the BUT. Such a pattern can then be compared to a known pattern for the same type of board to determine whether the BUT is faulty (shorts or opens) or not faulty. The most distinctive feature of this method is that testing PCBs by this method requires no electrical contact with the BUT due to the use of the energizing plate.

Abstract: A fixture for determining RF characteristics of a dielectric medium comprises a first coupler having an RF through-window with input and output ports, the input port connectable to a waveguide input. A second coupler has an RF through-window with input and output ports, the output port connectable to an output waveguide. A plurality of rods are aligned with the axes of the input and output waveguides and connect the output port of the first coupler to the input port of the second coupler. Each rod is passable through the dielectric media and mates with the input port so as to form a continuous waveguide passing through the dielectric media.

Abstract: The means and method of the present invention includes a source of microwave energy and associated elements which provide microwave energy to a petroleum stream. Other circuitry include elements which receive microwave energy from the petroleum stream. Electronic apparatus provides at least two outputs utilizing the provided microwave energy, the received microwave energy and known values for 100 percent oil, 100 percent solids of one specie and 100 percent water, corresponding to different ratios of ratios involving oil and water, oil and solids, and water and solids.

Abstract: The necessity for returning a repaired nose-mount type aircraft radar radome to a radar test range for recertification is avoided. Data representative of signal transmission characteristics of a repaired area of the radome wall is derived by use of transmission and reflection coefficient determination techniques. A small antenna radiates a test signal through the radome wall and the test signal is then reflected back to the same antenna now operating in a receiving mode. Reflected test signal data is gathered as the spacing of the reflector from the radome wall is successively changed and such data is used to derive signal transmission characteristics. Data representative of such transmission characteristics for a repaired area and a reference area can then be compared in order to detect the presence of out of specification conditions in the repaired area. In other applications, pre-recorded reference data can be used to accomplish certification testing of radomes as part of the manufacturing process.

Abstract: An apparatus and method to measure the unburnt carbon content of fly ash. A microwave signal is transmitted through or reflected from a fly ash sample and the attenuation or phase shift of the signal received by a detector/detectors is determined with respect to the incident signal and is used to provide a measure of unburnt carbon content. The detectors may be antennae means which also launch the incident signal or may be a completely separate means. A preferred embodiment comprises a microwave oscillator for launching the microwave signal into a fly ash sample in a microwave resonant cavity. Detectors determine the attenuation of phase shift of the received signal with respect to a signal from a reference microwave resonant cavity by the fly ash sample, and a measurement of the unburnt carbon content is obtained.

Abstract: An apparatus and method for measuring the permittivity of a polar solution specimen to enable a determination of the concentration of polar constituents in the specimen. The apparatus (10) employs a band pass filter including containment means (18) formed to contain the polar solution (26) therein and electrically dispose the polar solution (26) as a dielectric element in the band pass filter; conducting means (12); a source of electrical current (56) connected to said band pass filter; frequency variation means (52) electrically connected to the electric voltage source (56) to enable variation of the frequency at which current is applied to the band pass filter; and voltage sensing means (52) electrically connected to sense the peak voltage passed by the band pass filter.

Abstract: There is disclosed in the present specification a method and apparatus for use of a downhole formation multi-tester instrument in the characterization of formation fluids, including measurement of the conductivity of water, often in the presence of hydrocarbons under dynamic flow conditions and determining the hydrocarbon volume of the formation fluid. Utilizing a coaxial transmission line as a flow tube within the formation multi-tester instrument an electromagnetic wave is generated which propagates through the formation fluid in a transverse electromagnetic mode. Measurement of the phase shift and attenuation of the electromagnetic wave at points within the flow tube allow characterization of the fluid inside the cavity of the flow tube for dielectric constant and conductivity. Dielectric constant and conductivity can then be related to fluid conductivity and hydrocarbon volume.

Abstract: A system for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample.

Abstract: An apparatus and method for the measurement of, for example, the moisture in a material or, more generally, for the measurement of any material parameter which may be inferred by measuring the electromagnetic properties of the material under investigation. The meter apparatus comprises a controllable source of electromagnetic energy having stable selectable frequency. The controllable source of electromagnetic energy is coupled to a material measurement chamber by means of probes, loops, antennas, apertures or other structures so as to establish an electromagnetic field inside the measurement chamber thereby causing the field to interact with the material contained in the chamber. The method includes passing the process material through a frequency sensitive measurement cell. Exposing the process material to electromagnetic energy produced by a multi-frequency source. Generating an output signal having a distinctive frequency response characteristic.

Abstract: Method and apparatus for sensing fluid interface(s) in a complex fluid such as centrifuged blood, includes a sensing assembly with a microwave source and a microwave sensor positioned in spaced opposed relation, the microwave source and sensor defining a microwave propagation path. Relative motion is induced between the sample container and the microwave energy propagation path in the region between the source and sensor in a direction that intersects and is essentially perpendicular to the microwave energy propagation path; and processor apparatus responsive to the scanning apparatus and the modification in microwave energy sensed by the microwave sensor provides an indication(s) of the location(s) of a fluid interface(s) in the container.

Abstract: A portable device for use in the measurement of the dielectric properties of materials such as fish includes: a microwave circuit comprising a microwave source (10) connected via an isolator (12) to a directional coupler (14), a first output (16) of which is connected to a reference detector (18) and a first pre-amplifier (28) and a second output (20) of which is connected via an attenuator (22) to a sensor (24), an output of which is connected to a signal detector (26) and a second pre-amplifier (30); and further including two amplifiers (32, 34) into which outputs of the first (28) and second (30) pre-amplifiers are connected and a logarithmic/ratio device (38) which provides an output proportional to the logarithm of the ratio of outputs from the two amplifiers (32, 34), wherein an output from the logarithmic/ratio device (38) is calibrated to provide the content of a particular constituent of the material under test.

Abstract: Apparatus and a method for detecting the presence of incidental bubbles in liquid flowing in a tube. The system monitors the amplitude of microwave radiation from the liquid and recognizes when that amplitude drops in a manner characteristics of the presence of a bubble.

Abstract: A fixture for determining the dielectric properties of a test material having a housing with an electrically shielded cavity defined therein to hold test material that surrounds an electrical conductor. Input and output circuits for coupling microwave energy into and out of the electrical conductor in the cavity are provided, each circuit having a transmission line having a center conductor extending through the housing with a tapping mechanism midstream of the conductor for coupling energy from the center conductor of the input circuit into the electrical conductor and from the electrical conductor to the center conductor of the output circuit. The tapping mechanisms are adjustable to vary the coupling of microwave energy with respect to the electrical conductor.

Abstract: A device for measuring a multipactor effect in microwave systems includes a first coupler, a vacuum enclosure where a sample under test is enclosed, and a second coupler, all in series between an input which receives incident power and an output which delivers output power. The device also includes a mixer operated as a phase detector having a first input connected to an output of the first coupler to sample part of the input power via a first attenuator and a phase-shifter and a second input connected to an output of the second coupler to sample a part of the output power via a second attenuator. The output of the mixer is connected to a noise measuring device.

Abstract: Particular non-metallic materials are detected by a recognition of the way in which their electrical properties vary with the frequency of an applied alternating electric field. In one method a body being tested is subjected to electromagnetic radiation at each of a plurality of different frequencies, the pattern of variation of the body's reflectivity is evaluated and compared with stored information on the conductivity/frequency characteristic of the non-metallic material to be deleted. In another method a body being tested is subjected to a burst of electromagnetic energy and a measurement is made of the time taken for the body to retransmit energy absorbed from the burst.

Abstract: In the determination of the unburnt carbon content of fly ash, a microwave signal is transmitted through or reflected from a fly ash sample and the attenuation and phase shift of the transmitted or reflected signal from receiver antenna or circulator respectively, is determined with respect to the incident signal and used to provide a measure of unburnt carbon content. The invention is applicable to measurement of fly ash samples taken from a boiler outlet duct or for direct measurement of the unburnt carbon content of fly ash entrained in flue gas.

Abstract: A method for determining carbon content in fly ash includes providing a source of fly ash and a microwave interrogation chamber. A quantity of fly ash is introduced into the interrogation chamber and exposed to microwave energy. The amount of carbon in the fly ash is determined by measuring the amount of microwave energy exposed to the fly ash, the amount of energy transmitted through the fly ash, and the amount reflected therefrom in order to determine the amount of energy absorbed. The concentration of fly ash is preferably determined by determining the weight of the fly ash and determining the percentage of carbon content in the fly ash. The method is particularly useful in respect of monitoring carbon content in fly ash of boiler exhaust gases. The system may also be employed to determine the fly ash glass content of fly ash. An associated apparatus is also disclosed.

Abstract: The concentration of one liquid, such as water, in another liquid, such as crude or refined oil, existing in a mixture which also includes entrained gas is carried out by an apparatus which measures a change in a microwave oscillator operating frequency and the difference between incident and transmitted power with respect to a measurement section of the apparatus. Continuous monitoring of the difference in incident versus transmitted power is carried out to detect the presence of gas and then selectively averaged peak values of the concentration of one liquid in another are determined to provide an accurate measurement of the content of water in oil even with the presence of various amounts of entrained gas in the mixture.

Abstract: A full reversing millimeter test set comprising a pair of test head assemblies which are connected to an analyzer by means of coaxial cables enclosed within a sheath. Microwave signals are sent to the test head assemblies and therein frequency-multiplied so as to provide the necessary millimeter test signals required for testing microwave devices in the W band of 75-110 GHz. By placing the millimeter wave components in the test head assemblies, the phase distortions which would otherwise be encountered in flexing or movement of the interconnecting coaxial cables and the bulk, signal loss and phase distortions associated with long waveguide are eliminated.

Abstract: A method and apparatus for millimeter wave flow cytometry of a cell stream hydrodynamically focused in a zone of interaction with a millimeter wave source and complex ratiometric receiver. The cell stream is characterized by complex power wave scattering parameters as a function of frequency, scattering angle and polarization. These parameters train a signal processor to sort specimen cells into one of a plurality of predetermined reference groups in accordance with a minimum number of normal cell types and functional states.

Abstract: A method and apparatus measures dielectric properties over a broad range of frequencies. The functions of various resistivity and dielectric constant measuring devices such as logging tools are combined in a single tool. A measuring tool includes novel transmitting and receiving antennas. Electromagnetic energy flows to a transmitting antenna. A stripline adapter permits transmission to a stripline having a metallic central strip. A strip face is bent at approximately right angles, and has a length that is compatible with the desired frequency coverage. A ground plane extends from the stripline adapter to the right angle bend, and a void exists between the center strip and the ground plane. A dielectric is positioned to nearly fill the void. The antennas are positioned so that the strip face lies flush with the tool face, to permit electromagnetic energy to be transmitted into and out of the material to be analyzed.

Abstract: An arrangement for measuring, at a plurality of points, the microwave field diffracted by an object. A microwave radiation source illuminates an object. Electric doublet antennae loaded by diodes are disposed in line along the path of the radiation diffracted by the object. A guide structure, with coupling antennae, is disposed along the line of doublet antennae and collects the diffracted radiation. Electronic circuits control the whole so as to measure the diffracted field at the position of each doublet antenna.

Abstract: A millimeter and/or submillimeter network vector analyzer comprises a millimeter source and a millimeter heterodyne receiver, and the network to be analyzed is placed between the source and the receiver. The millimeter source comprises a first microwave source feeding a millimeter harmonic generator. The millimeter heterodyne receiver comprises a millimeter harmonic mixer which is fed by a second microwave source which serves as a local oscillator for it, an HF (high frequency) vector receiver and a device for displaying the characteristics of the analyzed network. The analyzer includes a device for servocontrolling the frequency of emission of the second microwave source by the frequency of the first microwave source (or conversely), and a main HF (high frequency) oscillator activating this servocontrol device. The main oscillator is also directly used as a phase reference for the HF (high frequency) vector receiver.

Abstract: A method and apparatus for determining carbon content in fly ash providing a source of fly ash and a microwave interrogation chamber. A quantity of fly ash is introduced into the interrogation chamber and exposed to microwave energy. The amount of carbon in the fly ash is determined by measuring the amount of microwave energy exposed to the fly ash, the amount of energy transmitted through the fly ash, and the amount reflected therefrom in order to determine the amount of energy absorbed. The concentration of fly ash is preferably determined by determining the weight of the fly ash and determining the percentage of carbon content in the fly ash. The method is particularly useful in respect of monitoring carbon content in fly ash of boiler exhaust gases. The system may also be employed to determine the fly ash glass content of fly ash.

Abstract: Radio frequency bridge techniques are used to parameterize the complex dielectric properties of solids, liquids, gasses and mixtures thereof. This parameterization is performed in an electrically isolated, physically open structure which allows continuous or batch monitoring of the materials and their mixtures. A method and apparatus are provided for measuring the composition of mutlicomponent process streams flowing in pipes or ducts. The method uses the pipe in which the mixture flows as a waveguide in which propagating radio frequency electromagnetic energy is induced through dielectric loaded apertures. The dielectric measurement is performed in an electrically isolated, flow through test section which induces constructive or destructive interference patterns at characteristics frequencies. The characteristic frequency determines the dielectric constant of the mixture. The dielectric properties are used in turn to determine mixture composition.

Abstract: A device for measuring the concentration of two substances through the transmission of electromagnetic waves. The device utilizes at least one transmission element for transmitting a signal and at least two receiving elements for receiving a signal from the at least one transmission element and providing first and second output signals. The present invention also utilizes a receiving device for receiving the first and second output signals from the at least two receiving elements such that the difference or ratio of the two signals is utilized to determine the concentration.

Abstract: A method for determining the dielectric properties of a test material using a housing with an electrically shielded cavity defined therein to hold test material that surround an electrical conductor. Input and output circuits for coupling microwave energy into and out of the electrical conductor in the cavity are provided, each circuit having a transmission line having a center conductor extending through the housing with a tapping mechanism midstream of the conductor for coupling energy from the center conductor of the input circuit into the electrical conductor and from the electrical conductor to the center conductor of the output circuit. The tapping mechanisms are adjustable to vary the coupling of microwave energy with respect to the electrical conductor.

Abstract: An apparatus and method for measuring the conductivity of a fluid. The apparatus 10 provides both a contact and non-contact monitoring of fluid conductivity by measuring the A.C. dielectric properties of the fluid. The apparatus 10 transmits an electromagnetic wave into the fluid 22 and analyzes the transmitted and reflected waves providing an indication of the conductivity of the fluid 22. The apparatus 10 is versatile in that it allows for the fluid to be in the form of a spray. In a specific illustrative implementation, a novel nozzle is provided to monitor the conductivity of paint spray 22 as it passes therethrough.

Abstract: A radome diagnostic system comprises a rotatably mounted turntable having support memebers for supporting a radome in a radome support area on the turntable, and a scanning assembly on the turntable for supporting a probe antenna in the radome support area and for translating the probe antenna in perpendicular x and y directions to cover a predetermined planar scanning area. A reference antenna is mounted on the turntable to provide a reference signal, and both the reference antenna and the probe antenna are connected to a suitable receiver for receiving signals from them and for suitably analyzing the collected data. A transmitter is located at a position remote from the turntable to direct radiation towards a radome mounted on the turntable. The probe antenna will detect radiation as degraded or modified by the effect of the presence of the radome in the radiation path. The reference antenna receives unperturbed radiation.

Abstract: A spectrometer for analyzing a sample substance which comprises a chamber (40) for supporting a sample to be analyzed. A gas drive circuit (42) communicates with the chamber (40) and the gas drive circuit (42) and chamber (40) are at least partly enclosed within a heated jacket (44). The gas flow through the gas circuit and chamber (40) entrains sample molecules in the flow and a nozzle (30) is provided to spray the gas flow and entrained molecules as a supersonic beam seeded with the molecules between a pair of plates (32 and 34) between which an electric field is created. The electrodes (32 and 34) comprise Stark electrodes. A microwave source (50) and a receiver (60) are arranged so that the source (50) produces a microwave beam which passes through the supersonic beam as the beam expands between the electrodes 32 and 34 which is detected by the detector 60. The detector 60 detects an absorption signal of the molecules which seed the supersonic beam.

Abstract: A level indicator for blood reservoirs, in particular of medical apparatus, having a level-responsive component to be provided on the wall of the blood reservoir is provided with an oscillator set to an operating frequency of greater than or equal to 50 MHz and having integrated into its circuit the level-responsive component which, when a preset limiting value is passed, changes the phase condition or amplitude condition decisive for the oscillation of the oscillator.

Abstract: A system and method for monitoring conditions in a fluid medium. A stream of the fluid medium is flowed through a fluid container which is electrically configured as a transmission line segment and which is electrically connected to load to UHF or microwave oscillator. The oscillator is not isolated from the load, and is operated free-running, at a starting frequency which is chosen to provide a particularly strong shift in permittivity of the fluid medium, as the chemical reaction progresses. Preferably the frequency and insertion loss of the oscillator are monitored, to gauge the progress of the reaction.

Abstract: The present invention is comprised of a non-intrusive microwave sensor system for measuring fluid saturation or multiple fluids contained within a flowline or a fluid saturated porous medium. Here, the microwave oil saturation scanner (MOSS) comprises a transmit portion and a measurement portion. The transmit portion generates two signals for different purposes. The first signal is used as a reference signal upon which the sample signal is eventually compared. The second signal is transmitted through the sample which causes a phase angle shift and signal attenuation. The two signals are then compared in the measurement portion where the phase angle shift and the signal attenuation is related to the concentration of oil and water in the sample mixture.

Abstract: Apparatus and method for measuring electric characteristics of sheet-like materials using an instrument which includes a waveguide tube member having one end connected to transmitter for introducing a microwave into the tube member and the other end fully opened, a waveguide terminal member having an opened end facing the opened end of the tube member to form slit of the whole wave guide body constituted from the tube and terminal members and having the other end connected to first microwave detector, and an auxiliary waveguide branching from the wall portion of said tube member adjacent to the slit with the branch-extension end being associated with a second microwave detector.

Abstract: A system for measuring the complex dielectric constant of a core sample is set forth. It incorporates a circular wave guide having a central axial transmitter coil. Equally spaced axial receiver coils are placed on both sides of the transmitter coil. The opposite polarity receiver signals are connected to an adder circuit to provide an output signal representing only the difference in the two received signals. By placing a standard such as air between the transmitter coil and one receiver coil, or core sample positioned between the transmitter coil and the other receiver coil provides a system for obtaining an output indicative of complex dielectric constant. Optionally, the system is operated in an oven to provide an elevated temperature, and can also be pressurized with a compressed fluid.

Abstract: Apparatus for measuring the concentration of one material such as water in another material such as crude or refined oil including a coaxial microwave transmission line formed by a conduit for receiving the material and a center conductor which is sheathed with a dielectric covering which is operable to prevent short circuiting of the transmission path. An oscillator circuit is coupled to the transmission line and is driven by a free-running voltage controlled oscillator and a signal receiver monitors the change in frequency caused by impedance pulling of the oscillator due to the change in the dielectric constant of the mixture. Incident and reflected or transmitted power with respect to the measurement section is measured to determine whether an oil-in-water or water-in-oil emulsion is present to verify the concentration of one fluid in the other for a particular operating frequency.

Abstract: A coaxial microwave absorption diagnostic device comprises a hollow cylindrical outer layer conductor with a coaxially aligned conductor rod extending therethrough and a dielectric material which interconnects the outer layer to the conductor rod. The device is formed with a passageway which is directed perpendicular to the longitudinal axis of the device and which passed through the outer layer, the conductor rod and the dielectric material. As so formed, the passageway is positioned for receiving a sample holder, such as a small capillary tube holding a sample solution. A variable or fixed frequency oscillator is electrically connected to an input end of the conductor rod for sending microwave power through the device and a diode senses the output portion of this microwave power which has passed through the device. The absorbed power, i.e. the input microwave power less the output microwave power, is determined by a comparator and used to analyze the sample.

Abstract: A method for analyzing a gas by means of microwave absorption including the steps of: generating a microwave at at least one frequency; continuously sweeping the microwave frequency over the absorption frequency of a known pure gas component; transmitting the microwave frequency to a measuring cell containing the gas to be measured and to a reference cell containing the known pure gas component; detecting an absorption measurement signal from the measuring cell; detecting an absorption reference signal from the reference cell; integrating the intensity of the measurement signal; and applying an alternating Stark voltage with a phase shift to the measuring cell and to the reference cell. Also provided is an apparatus which may be used in conjunction with this method.

Abstract: An electronic communication system monitor in one embodiment has sensors for sensing electrical and environmental conditions for communication system elements. Control relays connect the elements to a programmable controller. The programmable controller has a keyboard, display, printer and modem for remote communication of information; especially alarms providing notice of operating conditions outside acceptable parameters. A second embodiment provides a logic circuit connected to selected sensors which determines when a combination of conditions exist to cause alarm and automatically activates a remedial device to alleviate a potential problem.

Abstract: An improved RF shielding integrity monitoring system is provided for monitoring the shielding integrity of a shielded enclosure that accurately identifies degraded shielding effectiveness and leakage areas in the shielded enclosure. The RF shielding integrity monitoring system performs self-testing and self-diagnostic routines to assure proper system operation prior to monitoring of the shielded enclosure. The RF shielding integrity monitoring system includes a transmitter for transmitting predetermined transmitted by the shielded enclosure for receiving the signals; a receiver separated from the transmitted predetermined signals and for identifying the shielding effectiveness of the shielded enclosure; and a cable connected to the transmitter and the receiver for communicating signals between the transmitter and the reciever.

Abstract: A petroleum stream microwave water cut monitor includes test cell means which contains a reference petroleum multiphase fluid sample and which has a sample stream of a petroleum stream passing through it. A source transmits microwave energy to one of a first pair of antennae which irradiates the petroleum stream flowing in the test cell or the reference sample in the test cell with microwave energy. One of a second pair of antennae receives the microwave energy that has passed through either the petroleum stream or the reference sample. A detector detects the received microwave energy and provides a signal corresponding thereto. An indicator provides an indication of the water cut of the petroleum stream in accordance with the received signal power and a phase difference between the transmitted microwave energy and the received microwave energy.

Abstract: A microwave antenna structure couples electromagnetic microwave energy from a microwave transmission line into a sample contained in a sample container without invasion of the sample. The microwave antenna structure is formed by a bifilar helix of conducting first and second helical elements. The first and second helical elements are arranged in a parallel relationship defining a double helix with alternating spaced apart helical turns from the respective first and second helical elements. The double helix forms a holder for receiving and holding a sample container within the turns of the double helix. The first and second helical elements are formed with coupling extension for coupling to opposite polarity conductors of a microwave transmission line. Electromagnetic microwave energy propagating along the transmission line is coupled into sample material within the sample container.

Abstract: This disclosure relates to a technique for estimating the characteristics of a propagation channel by processing a cyclostationary signal which has passed through it. The technique extends to the use of this estimate to reduce the impact of the channel distortion on the recovered signal. Unique features of this technique include its ability to function even when strong interference is present with the cyclostationary signal of interest.

Abstract: A conjoint probe apparatus having an adjustable extendable probe end for embedding in the porous media for in situ sensing of changes in the dielectric constant of the carbonaceous constituents undergoing microwave pyrolysis, and a mechanism for indicating the sensed changes, for adjusting the radiation in dependence upon such changes, the degree of extension of the probe end being adjustable in dependence upon the sensed frequency of the attendant radiation.