Abstract: An ultrasound apparatus for measuring a fluid flow rate includes a processor which receives an analog signal from a receiver transducer then transforms it into a digitized signal used for determining the fluid flow rate. The processor includes a bandpass sigma-delta converter having a bandpass loop filter, and a digital-to-analog converter in a feedback loop.

Abstract: A universal calibration method and apparatus for nondestructive real time determination of moisture content in particulate or granular materials by radio-frequency sensors is described which is bulk-density and material-independent and remains valid across instruments of different designs.

Abstract: A material analyzing apparatus and associated method for analyzing. The apparatus comprises an analyzer body that contains a generally insulative material casing; a material analyzing circuitry that includes a transmitter, a receiver, and a control; an antenna system that includes a transmitting antenna, a receiving antenna, and a ground layer; a coupling structure that couples the antenna system to the material analyzing circuitry. The transmitter of the material analyzing circuitry generates a electromagnetic wave signal that is adapted to be sent by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receiving any returned signal from the material and send the returned signal to the receiver and control. The control then analyzes the signal for material characteristics, including at least one of density, material segregation, and moisture.

Abstract: A method of sensing moisture based on propagation-delay provides absolute readings of volumetric water content in a moisture-bearing medium without calibrating the sensor or its readings for the conductivity or temperature of the medium. A fast transition is launched on a transmission line that is immersed in the medium to be measured. The amplitude of the resultant waveform is analyzed at precise, programmable time increments by using a high-speed latching comparator. Firmware in a controlling microprocessor facilitates the successive reconstruction of the significant characteristics of the returning waveform. The microprocessor analyzes these characteristics to provide an accurate determination of propagation delay and conductivity, even for severely distorted waveforms. The moisture content of the medium is derived from the propagation delay.

Abstract: Systems, methods, and probe devices for electronic monitoring and characterization using absorbent media confined by a metallic mesh. The mesh allows a stream of liquid or gas to pass through the structure, so that the media will adsorb the material to which it is specific. This changes the permittivity of the media in which the electromagnetic field is propagating. This change in permittivity can be seen through the use of classical microwave methods such as phase shift, amplitude changes, frequency changes in a cavity or the frequency of an unbuffered oscillator. Some embodiments use a two cylinder structure, where an outer cylinder contains a material which selectively removes a chemical which may be in conflict with or would contaminate the sensing of the desired chemical. This outer cylinder does not play a part in the measurement because it is outside the metal shield which contains the measurement adsorbent, and is thus outside the electromagnetic field.

Abstract: A Moisture and Density Detector (MDD) that provides a method and apparatus to determine the moisture content and/or density of any dielectric material for various purposes. This device is very useful in detecting the moisture content (MC) of wood and wood-based materials, such as that of lumber in a dry kiln prior to, during and/or following drying. The MDD passes a radio frequency signal between opposed or adjacent capacitance electrodes and measures the signal strength and phase shift of the signal. The addition of phase shift and multiple frequencies improves the accuracy of the results.

Abstract: Separating drum 1 is provided with a device for determining the position, the composition and the nature of several layers of fluid settling upstream from barrier 8. The device comprises a first rod 12 provided with microwave beam emitters 13, a second rod 14 provided with microwave beam receivers 15, a microwave source 16 that can be connected to emitters 13, and means 17 for recording and analysing the microwave beams received by receivers 15.

Abstract: A moisture meter (1) has a hand-held casing (2) with a digital microcontroller (50), LCD display (4), and a keypad (3). Spring-loaded contacts (6) contact material and allow capacitive impedance measurement via electrodes (5) and drive/pickup circuits (20). Also, a relative humidity probe (9) provides an input so that the processor generates both moisture contact near-surface measurements and also relative humidity measurements. This allows optimum analysis of material.

Abstract: A material analyzing apparatus and associated method for analyzing. The apparatus comprises an analyzer body that contains a generally insulative material casing; a material analyzing circuitry that includes a transmitter, a receiver, and a control; an antenna system that includes a transmitting antenna, a receiving antenna, and a ground layer; a coupling structure that couples the antenna system to the material analyzing circuitry. The transmitter of the material analyzing circuitry generates a electromagnetic wave signal that is adapted to be sent by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receiving any returned signal from the material and send the returned signal to the receiver and control. The control then analyzes the signal for material characteristics, including at least one of density, material segregation, and moisture.

Abstract: A method for highly accurate, high speed, multi-slice density and moisture content measurements and calculations of homogeneous or non-homogeneous fibrous material, using a microwave resonator device and computer algorithms. The device is comprised of a cylindrical microwave resonator, including two cutoff waveguides, internal corrective pieces, a teflon tube, signal input and output ports, alternative microwave sources, alternative signal receivers, temperature sensor and optional moisture sensor, and computerized processing and display units. The method comprises passing fibrous material, located in-line of a production process, through the resonator, wherein the fibrous material is scanned with a sweeping range of microwave frequencies, in a continuous, real time, and multi-slice mode. The presence of the fibrous material causes resonance frequency shifts and changes in resonator quality, which are proportional to, and used in calculations of, material density and moisture content, respectively.

Abstract: The invention relates to a method and an arrangement for measuring a fluid. Electromagnetic radiation is used to measure the consistency, flow and/or gas content of a fluid flowing in a process pipe (102). At least two of the measurements are carried out substantially from the same measurement point in the fluid in a measuring tube (202) by utilizing one integrated measuring equipment (200) comprising transmitters and receivers for electromagnetic radiation in order to carry out the aforementioned at least two measurements.

Abstract: Apparatus for ascertaining the mass and/or the moisture content of successive increments of a running rod containing tobacco and/or filter material for tobacco smoke has a resonator housing with a cylindrical internal chamber which is disposed between an inlet and an outlet and wherein the rod is exposed to microwaves. The housing is made of a metallic material having a low thermal expansion coefficient, and its internal surface is lined with gold or another corrosion resistant substance. A protective plastic tube establishes a path for the rod from the inlet, across the chamber and into the outlet of the resonator housing.

Abstract: A microwave sensor (3) for measuring the relative proportions of fluids is provided. The sensor (3) includes a tube (4) having a length (9) for accommodating the fluids flowing through said tube. The length (9) of the tube (4) makes up a part of the sensor (3). Also included are probes (6, 7) for transmitting electromagnetic energy into the sensor (3) and receiving electromagnetic energy from the sensor (3). The sensor (3) uses resonance at a resonant frequency (fm) below the cut-off frequency (fm) of the tube (4). The tube (4) includes at least one radially extending, conducting, internal fin (5) extending along the axis (10) of the tube (4). The fin (5) may be of regular or irregular shape and may be fixedly or detachedly arranged, e.g., through a slot (13).

Abstract: The present invention relates to an apparatus for detection of foreign bodies in materials, comprising a first antenna device for transmitting electromagnetic signals, the transmitted electromagnetic signals are in the microwave range, the signals comprise at least two signals at different frequencies, a second antenna device for receiving signals originating from the first antenna, where the received signals, at least partially, passes through the materials, device for measuring at least one parameter of the received signals for each frequency, so as to obtain parameter values, device for comparing the parameter value with the corresponding output parameter value of the transmitted signals, so as to obtain a comparison value for each of the frequencies, device for analyzing each comparison value based on a reference value, which reference value is accessible to the apparatus, and device for emitting a signal when the comparison value differs a predetermined amount from the reference value.

Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: A method and apparatus for time domain reflectometry sensing of moisture in a test material. The sensor (200) having a generally helical shaped electrode (206) and at least one secondary electrode (208) spaced apart from the generally helical shaped electrode (206) to enable the test material to be present in the space (210) between the helical shaped electrode (206) and the secondary electrode (208). A wave pulse generator (202) is coupled to the generally helical shaped electrode (206) and the secondary electrode (208) that results in a reflection of the generated wave from the wave pulse generator (202). Additionally, a reflected pulse detector (204) is coupled to the generally helical shaped electrode (206) and the secondary electrode (208), in which the reflected wave pulse detector (204) receives a reflected wave pulse from the wave pulse generator (202).

Abstract: The system and the method are used for detecting a level of liquid metal at a given location, such as a launder set between an holding furnace and a casting pit. The system comprises an emitter coil and a receiver coil in a side-by-side configuration and in close proximity of the location. In use, an AC signal is applied to the emitter coil for producing an alternating magnetic flux. At least a part of the magnetic flux passes through the location where the level of liquid metal needs to be measured and goes back into the receiver coil. The signal in the receiver coil is monitored and the data are conveyed to a control module which determines the level of liquid metal from the variation of the signal in the receiver coil. The coils of the system are advantageously provided with respective core elements having a high magnetic permeability and which are configured and disposed to channel the magnetic flux.

Abstract: A method and device for determining the concentration of a medium other than air in an air/medium aerosol. The dielectric constant of the medium is measured using microwaves in a hollow conductor, with the aerosol passing through a neutral tube intersecting the hollow conductor. The microwave signal which propagates in the hollow conductor is subjected to attenuation and a phase shift due to the difference between the dielectric constant of the medium and that of air, the phase shift of the microwave signal being measured by taking into account the active path length (the tube in the cross section of the hollow conductor).

Abstract: An in-line, guided-microwave spectrometer has an antenna mounting assembly that is particularly useful in sanitary applications, such as food processing systems. The antenna mounting assembly reduces the likelihood of leakage that can corrupt the electrical operation of the system. The mounting assembly includes antenna cover plate which has a recess, and a dielectric antenna window body which has a flange which fits into the recess. The seam between the dielectric window body flange and the recess in the cover plate where adhesive is applied is isolated from an area of high pressure due to this configuration. Also, a back cover is preferably mounted over the back side of the antenna cover plate to protect electrical components on the back side of the cover plate during high pressure wash downs.

Abstract: Apparatus for ascertaining the mass and/or the moisture of succesive increments of a running rod containing tobacco and/or filter material for tobacco smoke having a resonator housing with a cylindrical internal chamber which is disposed between and inlet an outlet and wherein the rod is exposed to microwaves. The horsing is made of a metallic material having a low thermal expansion coefficient, and its internal surface is lined with gold or another corrosion resistant substance. A protective plastic tube establishes a path for the rod from the inlet, across the chamber and into the oulet of the resonator housing.

Abstract: The passive polarimetric microwave radiometer is a simple and low cost radiometric icing detection system that operates over a suitable set of frequency bands in the millimeter wave region of the spectrum to provide useful signatures for detecting aircraft icing conditions. This basic passive polarimetric microwave radiometer observes along a single line of sight and consists of a dual polarization dual frequency radiometer that is pointed in the direction of interest, such as the projected flight path, and operates at a frequency which is sensitive to the polarizing effects of hydrometeors. The passive polarimetric microwave radiometer could also observe in a horizontal plane around the aircraft or ground station and include both vertical and horizontal scanning capability.

Abstract: The method and structure of a moisture measuring device that creates an electric field, but substantially no related electromagnetic wave, and then determines a moisture content of a specimen based on the effect the moisture of the specimen has on the electric field.

Abstract: A moisture meter (1) has an LCD display (8) driven by a digital microcontroller (50) which generates digital moisture reading data. Readings are stored as discrete records in files. The microcontroller (51) stores a library of material data and automatically compensates signals from a capacitive/impedance sensor circuit (51) according to both stored material parameter values and sensed temperature. Users may edit the parameter values. A non-removable cover (4) is used at the final stage of production to configure the meter for the nature of interfacing (such as serial port interfacing) required.

Abstract: A method for determining warp potential of wood. One embodiment comprises nondestructively obtaining lengthwise shrinkage rates and grain angles of wood—such as trees, logs, or lumber—then determining warp potential of the wood based on the lengthwise shrinkage rates and grain angles. The method typically comprises measuring plural lengthwise shrinkage rates and plural grain angles to determine warp potential. Where the wood comprises lumber, lengthwise shrinkage rate and grain angle measurements typically are made on at least one major planar surface of the lumber at at least two measuring points separated by a predetermined distance, such as at substantially one-foot intervals along the lumber. Particular embodiments of the present invention determine lengthwise shrinkage rates using electromagnetic energy, acoustic energy, and combinations thereof. Working embodiments of the method use ultrasound energy to determine lengthwise shrinkage rates and grain angles.

Abstract: A method and apparatus for monitoring one or more parameters of a variable physical structure, such as liquid level, is disclosed. The method and apparatus includes an electrodynamic element placed in proximity to a monitored structure and exciting within said element an alternating electromagnetic field. The electromagnetic field should be at a frequency at which the electromagnetic field penetrates into the monitored structure and then variations of the electromagnetic field parameters are measured for the element caused by a variation in the structure. The exciting of the electrodynamic element is by an electromagnetic field in the form of at least one slowed electromagnetic wave having suitable energy distribution of the electric and magnetic fields for the measuring of the electromagnetic field parameters.

Abstract: A microwave transmission antenna arrangement for transmission of microwave signals from a position located in the adjacent vicinity of a bale transfer apparatus for transporting bales past the antenna for assessment of bale characteristics such as moisture in cotton including an antenna supported by a forgiving support by being relatively movable in position if a bale intercepts the antenna. The antenna is supported so as to be restored to a transmission and/or receiving position subsequent to any dislodgment as a result of any interception of a bale.

Abstract: The method and structure of a moisture measuring device that creates an electric field and then determines a moisture content of a specimen based on the effect the moisture of the specimen has on the electric field.

Abstract: A humidity sensor which utilizes microwave energy to determine a particular humidity value, e.g., a relative humidity, a specific humidity, or a dew point, without the need for delicate moving parts. The microwave humidity sensor requires little if any maintenance over a significantly long operational life, and is capable of highly accurate humidity measurements even at the extremes (e.g., toward 0% relative humidity and toward 100% relative humidity. In the disclosed embodiment, a microwave generator/transmitter is continuously or periodically pulsed to cause a known amount of microwave energy to be propelled through a metal tube structure, e.g., a waveguide tube structure. A microwave detector measures the amount of microwave energy at the other end of the tube structure.

Abstract: At least one characteristic, such as the mass/density and/or moisture content and/or dielectric constant, of a substance (such as the rod-like tobacco filler of a continuously advancing cigarette rod or a continuously advancing rod-like filler of filter material for tobacco smoke) is ascertained by an evaluating circuit receiving high-frequency signals from a resonator arrangement which receives microwave signals at least at two different frequencies from one or more microwave generators. The substance is caused to advance through a dielectric resonator of the resonator arrangement, and the high-frequency signals are influenced by the substance. For example, the circuit can compare first and second curves of high-frequency signals which respectively are and are n ot influenced by a selected substance; the curves can have sloping flanks and each of the two frequencies can be allocated to a sloping flank of a curve.

Abstract: A system for point-level detection of material within a vessel includes a transmission line probe adapted to be mounted to a wall of the vessel so as to extend within the vessel for contact with material when the material reaches a preselected level within the vessel. Electronics are operatively coupled to one end of the probe for launching microwave energy along the probe. The electronics are responsive to a change in microwave energy reflected from the free end of the probe within the vessel when the material is in contact with the probe, employing time-domain reflectometry techniques, for indicating that the material is in contact with the probe. This change in reflected microwave energy may comprise a change in phase or, more preferably, a change in apparent length of the probe resulting from contact with material having a higher dielectric constant than that of air when air surrounds the probe.

Abstract: An apparatus (10) and methods for testing the quality of foundry green sand. The apparatus includes three testing stations where filling (60), compaction (80), weighting (94), gas permeability testing (120), moisture testing (40), fracture testing (160), and shear testing (180) occur. Each station is automated and controlled by a computer programmed control system or controller (200). Known foundry sand testing formulas are entered into the system or controller which in turn receives input from each of the testing stations. The condition and quality of the foundry sand is output. A method for testing is also disclosed.

Abstract: A method for predicting the bulk density of coal after it is dropped from a known height into a container from measurements of bulk density and moisture content of the coal before it is dropped into the container. The method includes obtaining a plurality of samples of coal, measuring the bulk density of each coal sample by directing nuclear radiation through the coal, subsequently dropping each sample from said known height in a test facility and measuring the bulk density of each coal sample after drop, measuring the moisture content of each coal sample, determining a correlation between the bulk density of said coal samples after drop with the bulk density determined before drop and the moisture content, and predicting the bulk density of coal after drop into a container from subsequent measurement of the bulk density and moisture content and the previously determined correlation from test facility measurements.

Abstract: A method and system for measuring the moisture content and internal structure of a material which is either packaged as a module or presented in a continues bulk flow. A frequency modulated digital pulse of very high frequency microwaves is directed through the material under analysis by a microwave transmitter. A microwave receiver receives the microwave signal after it exits the material on the opposite side to that of the microwave transmitter. The attenuation and time delay of the exit signal are analyzed and corrected with empirically derived functions so as to calculate the moisture content and density, respectively, of the material. Irregularity of the internal structure of the material is determined by comparing the calculated densities of multiple slices of the material with each other.

Abstract: A method of determining the moisture content of a module of tobacco material, the method comprising the steps of: (a) transmitting a plurality of microwaves substantially through a portion of the module, such that the microwaves are transmitted microwaves; (b) receiving the transmitted microwaves such that the microwaves are received microwaves; (c) determining a phase shift and an attenuation from the received microwaves; (d) repeating steps (a) to (c) for at least a portion of the material on the module, such that a plurality of phase shifts and a plurality of attenuations is obtained; (e) using at least one empirical factor selected from the group consisting of weight of the module, temperature of the module, shape of the module and type of the material to correct the plurality of attenuations, producing a plurality of corrected attenuations; (f) calculating a raw moisture content of the material from the corrected attenuations; (g) determining a density of the material from the phase shifts; and (h) calcu

Abstract: A phase shift oscillator circuit having a delay line in a feedback loop is employed to determine soil moisture content and water level. The delay line is connected to the oscillator such that the dielectric value of the medium inside the delay line influences the frequency of the oscillator circuit. The delay line is placed in the medium to be studied. Soil moisture content and water level are calculated as a function of the frequency of the oscillator output, and changes in soil moisture content or water level are calculated as a function of changes in oscillator frequency over time. An elongated delay line is employed to measure water level.

Abstract: A method of determining the moisture content of material on a bobbin featuring a hollow core, the method comprising the steps of: (a) transmitting a plurality of microwaves substantially through a portion of the bobbin, such that the microwaves are transmitted microwaves; (b) receiving the transmitted microwaves such that the microwaves are received microwaves; (c) determining a phase shift and an attenuation from the received microwaves; (d) repeating steps (a) to (c) for at least a portion of the material on the bobbin, such that a plurality of phase shifts and a plurality of attentuations is obtained; (e) using at least one empirical factor selected from the group consisting of weight of the bobbin, temperature of the bobbin, shape of the bobbin and type of the material to correct the plurality of attenuations, producing a plurality of corrected attenuations; (f) calculating a raw moisture content of the material from the corrected attenuations; (g) correcting the plurality of phase shifts for an artefact

Abstract: The invention relates to a method for measuring gas content in a fluid, such as papermaking pulp or coating paste, and to a gas content measuring device. Pressure variations generated by a pump, for instance, are to occur in the fluid. Travel time, phase and/or attenuation of the microwave signal (20) are measured with the gas content measuring device while the signal (20) penetrates through the fluid (13), and the gas content is determined on the basis of changes in travel time, phase and/or attenuation of the microwave signal (20) caused by pressure variations of the fluid (13).

Abstract: A radiometer and a method for indicating water content and water content change caused by water and/or liquid water are disclosed. According to the method, changes of noise temperature values are observed by receiving microwave electromagnetic radiation at a medium frequency. This medium frequency is considerably below the lowest absorption resonance (approximately 22 GHz) of water molecules. At least one noise temperature value is set as reference value, and noise temperature changes are compared with the reference level.

Abstract: A microwave resonator for connection to an instrument for measuring the density and/or moisture profile in the longitudinal direction of a sample, which microwave resonator has a through-hole (3) at right angles to its area extent, which through-hole (3) is bounded by metallic walls (4) extending in the longitudinal direction, distinguishes itself in that the interior (1) of the resonator is essentially flat, with a thickness which is considerably less than the lateral dimensions at right angles to it, and in that the resonator is filled with a dielectric.

Abstract: A phase difference measuring apparatus obtains a first receive signal by transmitting and receiving a to-be-measured material in a reference state and a second receive signal by transmitting and receiving a signal wave to and from that material in a measured state. The apparatus finds a reference phase difference .theta..sub.1 from the transmit wave and first receive signal and an apparent phase difference .theta..sub.2 ' from the transmit wave and second receive signal. The apparatus adds the apparent phase difference .theta..sub.2 ' to a product of the number of rotations, n, the apparent phase difference .theta..sub.2 ' passes through a given reference point and an angle of 360.degree. to find a true phase difference .theta..sub.2. The apparatus varies the number of rotations, n, to n+1 when the apparent phase difference .theta..sub.2 ', while being increased, passes through the reference point and that number of rotations, n, to n=n-1 when the apparent phase difference .theta..sub.

Abstract: A monitor for monitoring the moisture content of grain comprises at least one programmable PIN diode attenuator connected between a microwave measurement signal source and a transmit antenna. A controller stores an addressable attenuation table, each location in the table storing an attenuation value and an associated attenuator address. A counter accesses the table locations sequentially and the attenuator addresses are applied to the attenuator to cause a step-wise decreasing attenuation of the measurement signal which is then transmitted through the grain. After the signal passes through the grain, it is detected and applied to a threshold comparator. When the magnitude of the detected signal reaches the threshold, the counter is stopped and the attenuation value at the location pointed to by the counter is taken as the attenuation of the measurement due to moisture in the grain. Once the attenuation has been determined, the moisture content and mass grain flow may be calculated.

Abstract: Apparatus for insertion in a well which is producing fluids from multiple zones for measuring the concentration of water in the fluids flowing through the well to determine which zone may be producing excessive quantities of water. The apparatus transmits microwave frequency range radiation within a section of the wellbore. The apparatus may utilize a portion of the well casing and a conductor member which is centered in the wellbore by spaced apart centralizers to form a coaxial transmission line within the wellbore. The apparatus may be traversed through the wellbore on a wireline type cable for continuous measurement of the water content of the water-oil mixture flowing through the well to determine which zone is producing excessive amounts of water into the production fluids.

Abstract: A water adding control apparatus includes a microwave detecting unit which enables the detection of microwave value proportional to the water content amount of the water added grain and which makes it unnecessary to make calculations for an estimated water content value of the water added grains. The water adding process is started by inputting initial water adding amount, the microwave value of the raw grain after the addition of water is measured, the measured microwave value is set as the target microwave value which serves as control reference, and the water adding amount is feed-back controlled for the actually measured microwave value to constantly match the target microwave value.

Abstract: A device for measuring the moisture content of a module of material, including: (a) a source of microwave radiation for producing a microwave radiation source beam, at least a portion of the source being located on one side of the module; (b) at least one microwave antenna located on an opposing side of the module for receiving an exit beam and for producing an antenna signal, the exit beam being the source beam after a transition from the source to the antenna; (c) an attenuation unit for receiving a first portion of the antenna signal and for measuring an attenuation of the antenna signal; (d) a phase shift determiner for receiving a portion of the source beam and a second portion of the antenna signal and for determining a phase shift of the source beam and the antenna signal, the phase shift determiner including: (i) a raw phase shift measurer for determining a raw phase shift of the source beam and the antenna signal; and (ii) a phase region determiner for determining a phase region of the raw phase shif

Abstract: A moisture detection meter (10) has a sensing head having a single chamber (11) with an open top. A dielectric resonator member (14) is provided in the chamber. The sensing head also has a field generator (17) to generate an oscillating electric fluid in the chamber. The resonator member (14) and the field interact to produce at least one field component which is directed out of the open top of the chamber to interact with stock passing over the sensing head. A detection device is also provided to detect the frequency of resonance of the field compact after interaction with the stock and an indicator device is provided so as to give an output indicative of the moisture content of the stock.

Abstract: Moisture sensing apparatus that uses slow wave transmission lines. Such transmission lines include a helically wound inner core, a surrounding outer conductor, and a moisture bearing material between the inner core and the outer conductor. Preferably, the transmission line includes a moisture barrier that separates the transmission line into a sealed dry section and a wet section which is in moisture communication with its environment. The moisture sensing apparatus further includes a source of electrical signals on the transmission line, and a moisture sensing circuit, operatively connected to the slow wave transmission line, which senses the moisture content of the moisture bearing material from the velocity of the impressed electrical signals on the slow wave transmission line. Preferably, the velocity of the impressed electrical signals is obtained indirectly using a sing-around measurement technique.

Abstract: A device and method for determining the proportion of the phases of a multiphase fluid is disclosed. The device includes microwave emission and reception devices which are suited to the composition variation of the multiphase fluid, a processor and control for determining directly, from measurements of amplitude and phase shift of a beam crossing the multiphase medium and a rate of occupation of liquid phase and/or a gas phase for a given section of the pipe. The flow rate of each of the phases is determined.

Abstract: A radiometer system detects naturally occurring atmospheric microwave radiation in three bands at approximately 20, 30, and 90 GHz. Signals representing radiation intensity at each of these bands is converted into a brightness temperature and used as a system input to a processing system that yields system outputs including the atmospheric ice water path, liquid water path, and water vapor content. A parameterized radiative transfer model is used to quantify radiation emanating from the atmosphere. The applied signal processing technique provides measurement of the total ice column in the atmosphere, and simultaneously provides accurate measurement of water vapor and liquid water. A calibration technique enhances the accuracy of ice detection measurements by correcting for the effects of absorptive atmospheric components, such as water vapor and liquid water.

Abstract: A portable microwave measurement instrument is disclosed for measuring an unknown property of a test material, such as moisture content, by generating and transmitting two microwave beams of different frequency through such material so a portion of the beam energy is absorbed by the moisture. The corresponding attenuated received signals are compared in order to compensate for the presence of a component in the test material, which is not being measured but which also absorbs microwave beam energy. A temperature compensation circuit using two thermistors is connected to the PIN diode attenuators to adjust their attenuation characteristics in compensation for changes in temperature. To determine the density of the test material, one of the microwave signals is used to measure the phase shift of the corresponding received signal and produce a phase shift output signal.

Abstract: A phase difference measuring apparatus obtains a first receive signal by transmitting and receiving a to-be-measured material in a reference state and a second receive signal by transmitting and receiving a signal wave to and from that material in a measured state. The apparatus finds a reference phase difference .theta..sub.1 from the transmit wave and first receive signal and an apparent phase difference .theta..sub.2 ' from the transmit wave and second receive signal. The apparatus adds the apparent phase difference .theta..sub.2 ' to a product of the number of rotations, n, the apparent phase difference .theta..sub.2 ' passes through a given reference point and an angle of 360.degree. to find a true phase difference .theta..sub.2. The apparatus varies the number of rotations, n, to n+1 when the apparent phase difference .theta..sub.2 ', while being increased, passes through the reference point and that number of rotations, n, to n=n-1 when the apparent phase difference .theta..sub.