Abstract: A microwave position sensing system includes a plurality of target components that each move between multiple positions. A microwave generator produces a microwave frequency signal. A divider receives the microwave frequency signal and splits the microwave frequency signal into a plurality of position sensing signals. The position sensing signals are respectively sent to the plurality of target components to determine a position of each of the target components. Each position sensing signal may also be calibrated. In one example, first and second frequencies are transmitted through a common wave guide. The first frequency is reflected prior to reaching the target component to produce a calibration signal. The second signal, which is used to detect the position of the target component, is calibrated using the first frequency.

Abstract: An antenna for a fill level radar includes a high-temperature process separation device and an attenuation element. The attenuation element is used to improve the measuring signal in the near zone of the antenna and is affixed to the process separation device or in the process separation device. In this way antenna ringing may be significantly reduced.

Abstract: A device (1; 1b) for measuring the thickness of a layer of material (20) is provided with reading means (2) and control means (3) connected to the reading means (2). The reading means (2) include a microwave planar type sensor (6) and an A/D converter (8) connected to the microwave sensor (6) and arranged in proximity of the microwave sensor (6).

Abstract: A position detecting device serves for finding the distance between a specimen arranged in a conductive structure and a microwave antenna arrangement of the position detecting device, produced by an inventive method, on the basis of microwaves. The microwave antenna arrangement exhibits a dielectric antenna body provided at least in part with an electrically conductive coating, which constitutes a first and a second pole face on a coupling probe of the microwave antenna arrangement.

Abstract: Method and apparatus for analyzing a substance in a container, the method comprising the steps of: disposing antenna means (3) at a predetermined geometrical distance (L) from a container portion (13); transmitting a signal from said antenna means through a surface portion (12) of the substance towards said container portion; receiving a first reflected signal in said antenna means from said container portion; determining a geometrical distance (L1) from the surface portion to the container portion; varying the frequency of the transmitted signal to determine a first phase displacement between the transmitted signal and the first reflected signal; determining an optical distance from the surface portion to the container portion based on the first phase displacement; and determining the index of refraction (nt) of said substance based on the optical and geometrical from the surface portion to the container portion.

Abstract: A system and method for measuring a thickness of a refractory wall of a gasifier using electromagnetic energy is disclosed. The system includes a waveguide with a bistatic or monostatic phased array antenna at one end. The waveguide is operably connected to a Network Analyzer that generates a pulse of electromagnetic energy with a desired bandwidth. The pulse is transmitted through a coaxial cable to the waveguide. The reflection of the pulse is received by the waveguide and input to a data acquisition system.

Abstract: In fill-level measuring devices according to the pulse-transit-time method, a reflection that is generated internally in a microwave module is used as a reference for transit time measuring. For generating the reference pulse, the microwave module comprises its own sampling mixer or its own oscillator. Subsequently, the echo signal and the reference pulse can be further processed separately or together. No delay line is necessary on the transmission frequency of the radar sensor. Interference as a result of leakage signals is largely prevented.

Abstract: Wet and dry film thickness can be measured non-invasively on structures, such as surfaces associated with vessels, aircraft and buildings, using calibrated microwave sensors. The film is measured by directing microwave energy toward the film. The microwave energy passes through the film and is reflected by a reflective or semi-reflective substrate surface below the film. Properties of the reflected wave are compared with properties of reflected waves that were passed through calibration samples of known thicknesses to determine the unknown thickness of the film. In some embodiments, one or more sensors are maintained at a fixed altitude above the conductive/semi-conductive substrate for measurement, and in other embodiments, one or more sensors are maintained at a fixed altitude above the film.

Abstract: A system or method for counting the number of layers of a multilayer object is adapted for counting the number of layers by means of a simple arrangement of emitting an electromagnetic wave to strike the object that is in a multilayer state. In the system or method, an electromagnetic wave is caused to strike at least either the top surface or the bottom surface of a multilayer object and electromagnetic waves generated by reflection of the incident electromagnetic wave at the respective interfaces of the layers of the multilayer object or an electromagnetic wave generated by transmission of the electromagnetic wave through the multilayer object.

Abstract: A device for determining distance between a rotor blade and a wall of a gas turbine surrounding the rotor blade is provided. A waveguide guides and emits electromagnetic waves of at least one frequency in the direction of the rotor blade through a waveguide opening facing the rotor blade. The electromagnetic waves are injected into the waveguide and reflected portions of the electromagnetic waves are received. An evaluation unit compares the phase of the electromagnetic waves to be injected with the phase of the reflected portions of the electromagnetic waves and determines phase comparison values for every frequency and the distance is determined based on the phase comparison values. The waveguide comprises a sealing element which is configured to be transmissible for the electromagnetic waves of the frequency and which has two opposite surfaces in the direction of guidance of the electromagnetic waves.

Abstract: A microwave sending antenna 3R and a microwave receiving antenna 4R are provided to a right-side furnace wall 1R, and the system is devised so that the microwaves emitted from the microwave sending antenna 3R are reflected by the right-side edge of a cold-rolled steel plate 2, and the reflected waves are received by the microwave receiving antenna 4R. Similarly, a microwave sending antenna 3L and a microwave receiving antenna 4L are provided to a left-side furnace wall 1L, and the system is devised so that the microwaves emitted from the microwave sending antenna 3L are reflected by the left-side edge of the cold-rolled steel plate 2, and the reflected waves are received by the microwave receiving antenna 4L. If the time from the sending of the microwaves until the receiving of the reflected waves is designated as t, and the velocity of the microwaves is designated as c, then the distance to the object reflecting the microwaves is determined from t·c/2.

Abstract: A method for determining the composition and water salinity of a multi-component mixture of a gas and at least one liquid, including water, in a pipe (1), the method comprising the following steps: a. electromagnetic phase measurements are performed between two receiving antennas (4) located at different distances from a sending antenna (3), b. based on an empirically determined constant(s) and the above measurements, the effective and imaginary dielectric constants are determined, c. the mixture density is determined, d. the temperature and pressure are determined e. based on the knowledge of densities, effective dielectric constants and imaginary dielectric constants of the components of the fluid mixture and the results of the above steps a-d, the volume fractions of the gas and liquid or liquids of the fluid mixture and salinity of the water are calculated. An apparatus for performing the method is also disclosed.

Abstract: Described herein is a method for measuring, via a microwave sensor, the thickness of a layer of first material, said method envisaging: acquiring at least one frequency response of the layer of first material via a microwave sensor; setting the microwave sensor on a plurality of specimens of second materials for different temperature values in such a way as to obtain reference data; calibrating the microwave sensor as a function of the electrical conductivity of the first material using the reference data; measuring the temperature of the layer of first material via a temperature sensor; determining measurement parameters from the frequency response; and processing the reference data with the measurement parameters to obtain a measurement of the thickness of the layer of first material.

Abstract: An object to be measured is measured using microwave radiation. Oscillation energy is generated by means of a feedback coupled active unit. The solution involves generating resonance into at least one oscillator, each oscillator comprising at least one open resonator, each resonator being coupled to at least one active unit, by using the object to be measured as a functional part of the resonator, the object to be measured causing a resonance frequency dependent on the location of a surface of the object to be measured to be generated in each oscillator. A measurement part determines at least one characteristic of the object to be measured on the basis of the resonance frequency of each oscillator.

Abstract: A sensor probe for time domain reflectometry may include a plurality of flexible elongated strips of an electrically conductive material extending from a proximal end portion of the probe to a distal end portion thereof. Each of the elongated strips can be substantially coplanar relative to each other along a path that is transverse to a longitudinal axis of the probe, and the plurality of elongated strips also being in a substantially parallel arrangement along the length of the probe. A flexible substrate of an insulating material can be attached to the sheets to maintain the sheets in the substantially parallel and coplanar arrangement. A connector is electrically coupled to the strips for providing communication of electrical signals relative to the strips.

Abstract: A horn antenna suitable for use with a level measurement device and having a composite emitter structure. The emitter structure or assembly comprises an emitter and a plug. The emitter provides the process interface and is formed from a material having properties which include microwave transparency, chemical resistance and/or mechanical strength. The plug is isolated or partitioned from the process interface. The plug is formed from a material different from the emitter and exhibits the properties of microwave transparency and/or mechanical strength. According to another aspect, the level measurement device includes a coupling mechanism which allows the removal of the horn antenna independently of the emitter.

Abstract: A level measurement arrangement for measurement of a level of a product in a container, comprising: a level sensor, having: a mounting element, including a process connector, for mounting the mounting element on a mating counter connector on an opening of the container, and a conductive probe segment extending from the mounting element into the container; a conductive probe extension (19), having a first end, which is permanently fixed to an inner wall of the container, and having a second end, which is detachably connectable to an end of the conductive probe segment extending into the container; and sensor electronics comprising elements for generating and sending short electromagnetic pulses down the probe segment and the probe extension, elements for reception of the echoes of the pulses reflected at a surface of the product elements for determining the level of the product in the container, based on a time of flight needed for a pulse to travel down the probe segment and the probe extension, and its echo

Abstract: A circuit for a radar level gauge for measuring the level of the surface of a product stored in a container, wherein the gauge includes a radar for transmitting microwave signals from a multiband antenna unit towards the surface for receiving microwave signals reflected by the surface and for determining the level based on an evaluation of the time lapsed between the received and the transmitted signals and said radar operating on at least two different frequency bands. The circuit includes: a first microwave provision means for providing a microwave signal of a first frequency band having a first center frequency, a second microwave provision means for providing a microwave signal of a second frequency band having a second center frequency. The ratio between the second and the first center frequency is quantified as at least greater than 1.5:1 and preferably greater than 2:1.

Abstract: A machine includes a static member and a moving member. The moving member includes a central hub and a moving component. The moving component includes a first end portion fixedly connected to the central hub, a second end portion and an intermediate portion. The second end portion of the moving member is spaced from the static member so as to form a gap. A transmitting element is mounted to one of the static member and the moving member. The transmitting element emits an acoustic wave having a predetermined frequency across the gap. A receiving element is mounted to the other of the static member and the moving member. The receiving element receives the acoustic wave from the transmitting element. The machine further includes a controller that determines a clearance distance extending between the moving member and the static member based on the acoustic wave passing across the gap.

Abstract: The invention concerns an antenna system for level measurement with a level measurement device with a wave guide (5) that runs axially and that either has on its rear side an arrangement (4) for the generating and interpreting electromagnetic waves or can be connected to such an arrangement of an antenna, in particular, a parabolic antenna (1-3) on the front side of the wave guide and a wave adapter (9) for transmitting such a wave between two components of the arrangement that conduct the wave for adaptation of the wave transmission between the components, whereby the wave adapter has a through opening in the axial direction.

Abstract: Both in potential separation in the microwave path, and in potential separation directly between the two-wire loop and the output circuit, the quality of signal transmission may be negatively affected. A filling level radar device with potential separation within the electronics unit is stated, wherein potential separation does not separate analogue signals but instead separates digital signals or direct-current-free alternating signals. For example, the separation line leads through digital signal connections or alternating-voltage signal connections. As a result of this the expenditure for potential separation may be reduced and the transmission quality may be improved.

Abstract: A method determines the layer thickness of a TBC coating of at least one blade of a non-positive-displacement machine. To this end, at least one electromagnetic wave is emitted to the surface of the at least one blade, the at least one electromagnetic wave is then at least partially reflected by the at least one blade, and the reflected portion of the at least one electromagnetic wave is received and subsequently processed. In addition, the at least one electromagnetic wave is emitted with a frequency matched to the layer thickness of the TBC coating, and the phase of the at least one electromagnetic wave is compared with the phase of the at least one received electromagnetic wave. The at least one emitted electromagnetic wave undergoes a phase change during reflection and the layer thickness of the TBC coating is determined by the phase comparison.

Abstract: Methods of detecting an interface between materials having different dielectric loss factors using an apparatus having a transmission line including an inner conductor surrounded by dielectric and a shielding conductor are disclosed. Sublengths of inner conductor are exposed along the line, with adjacent sublengths being separated by shielded sublengths. In one embodiment the apparatus is excited by a signal and inserted into the materials to a predetermined depth. Signal attenuation is measured. The interface between strata is identified based upon signal attenuation. In another embodiment the apparatus is excited by a signal and progressively inserted into the materials. Apparatus position is tracked and t-he attenuation of the signal is monitored as a function of insertion distance to detect ranges having a substantial rate of change of attenuation and ranges having substantially no change of attenuation. The interface is identified based upon differences in the rate of change in attenuation.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: An antenna for a level sensing gauge comprises an environmentally sealed chamber extending from the level sensing gauge and mounting and positionable within the interior of a storage compartment, including a breathable aperture for permitting pressure and humidity equalization between the interior of said chamber and an exterior environment.

Abstract: Apparatus and method are described for measuring the location and speed of an object, such as instrumentation on a movable platform, disposed within a pipe, using continuous-wave, amplitude-modulated microwave radiation.

Abstract: A system and method for sensing the proximity of an electronic device, in particular, a radio frequency mobile communication device such as a mobile telephone, wireless modem equipped portable computer, or the like to a body employs an antenna capable of altering its impedance for changing the amount of radio frequency electromagnetic energy reflected by the antenna when the antenna is in proximity to the body. The radio frequency electromagnetic energy reflected by the antenna is measured and used for determining proximity of the antenna to the body.

Abstract: Wet and dry film thickness can be measured non-invasively on structures, such as surfaces associated with vessels, aircraft and buildings, using calibrated microwave sensors. The film is measured by directing microwave energy toward the film. The microwave energy passes through the film and is reflected by a reflective or semi-reflective substrate surface below the film. Properties of the reflected wave are compared with properties of reflected waves that were passed through calibration samples of known thicknesses to determine the unknown thickness of the film. In some embodiments, one or more sensors are maintained at a fixed altitude above the conductive/semi-conductive substrate for measurement, and in other embodiments, one or more sensors are maintained at a fixed altitude above the film.

Abstract: A radar level gauge (RLG) using electromagnetic waves for determining a process variable of a product in a tank is provided which includes timing circuitry adapted to provide timing control of a transceiver, and a communication interface arranged to receive power in an intrinsically safe manner and to connect the radar level gauge externally thereof. The RLG further comprises an isolation interface arranged to galvanically isolate the transceiver from the timing circuitry and the communication interface, the isolation interface being arranged to transfer power and timing control from the timing circuitry and the communication interface to the transceiver circuitry.

Abstract: A position detecting device finds the position of a specimen arranged in a conductive structure on the basis of microwaves and includes an electrical circuit for the production and/or reception of the microwaves and a microwave antenna arrangement for emitting and/or receiving the microwaves. Said position detecting device includes a dielectric antenna body with a first pole face and a second pole face for the transmission of microwaves. The antenna body forms a component of the microwave antenna arrangement. The electrical circuit is at least in part arranged on the antenna body.

Abstract: The invention relates to a system, device, and method for using radar signals to measure the distance (h) to a surface from said device, the device comprising a transmitter and a transmitting antenna for transmitting radar signals, and a receiver and a receiving antenna for receiving a radar signal. The device may also comprise a first additional reflecting object separate from the receiving antenna, which additional reflector is designed so as to introduce a first predetermined alteration in radar signals upon reflection, with the device being equipped with means to differ between received signals with and without said predetermined alteration. The first predetermined alteration introduced by the first separate reflector can be, for example, a modulation shift or a shift in the polarization of the signal. In a typical embodiment the additional reflector is located close to the radar unit creating a double transition from radar unit to the surface.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: A power tool (1) for driving a working tool (3) that penetrates at least axially into a to-be-machined material (2), and including a signal processor (6, 6?), and a transducer (5) which is suitable for exciting and detecting a high-frequency electromagnetic wave (4) propagating axially along the working tool (3) and which is connected to the signal processor (6, 6?) that is designed to determine the penetration depth (T) of the working tool (3) into the material (2) based on high-frequency electromagnetic waves (4).

Abstract: A protection circuit for a current loop powered level measurement or time of flight ranging apparatus. The protection circuit includes one or more Zener diodes, a leakage current detector circuit and a compensating current circuit. The leakage current detector circuit detects the leakage currents flowing from the Zener diodes and generates an output for the compensating current circuit. The compensating current circuit generates a compensating current so that the sum of the leakage currents and the compensating current remains a constant and the loop current is not affected by variations in the leakage currents for example as a result of variations in the voltage in the current loop or temperature of the device.

Abstract: A level measurement device to measure the fill level of a fluid in a container, and a method to determine the contents level of a first fluid in a container and a presence of a second fluid below the first fluid. Microwave signals generated in the level measurement device are guided on a wave guide that is immersed in the first liquid. The measurement curve from received measurement signals is scanned for a first signal peak indicating a first fluid surface. The measurement curve is also scanned for a potential second signal peak having the same polarity as the first signal peak and thus indicating an interface between the first and a second fluid.

Abstract: A method is provided and includes exciting a sensor with an incident signal and generating a reflected signal by reflecting the incident signal from the sensor. The incident signal and the reflected signal interfere to form a standing wave. The method also includes processing the signals to determine a sensed parameter based upon a frequency at which the standing wave exhibits a null.

Abstract: A microwave measurement system is utilized for the determination of displacement of a piston in a fluid filled cylindrical structure. The piston plus cylindrical encasement of the hydraulic system is modeled as a uniform cylindrical waveguide terminated in a metal plate. A novel shaped probe antenna to measure the slope of the relative phase of the reflected equivalent voltage wave with respect to frequency. The idea to measure the slope of the relative phase is novel and requires a new antenna structure. Instead of using the phase slope with respect to frequency, the total phase shift in a given frequency range is used to determine the location of the piston in the cylindrical chamber. Simulation and measurement will be used to determine the impedance of the antenna as well as the electromagnetic field at different locations inside the cylinder. In addition, the antenna will be analyzed to optimize its design, which ought to result in minimizing the reflections.

Abstract: A precision pulse detection system for time-of-flight sensors detects a zero axis crossing of a pulse after it crosses above and then falls below a threshold. Transmit and receive pulses flow through a common expanded-time receiver path to precision transmit and receive pulse detectors in a differential configuration. The detectors trigger on zero axis crossings that occur immediately after pulse lobes exceed and then drop below a threshold. Range errors caused by receiver variations cancel since transmit and receive pulses are affected equally. The system exhibits range measurement accuracies on the order of 1-picosecond without calibration even when used with transmitted pulse widths on the order of 500 picoseconds. The system can provide sub-millimeter accurate TDR, laser and radar sensors for measuring tank fill levels or for precision radiolocation systems including digital handwriting capture.

Abstract: A method for detecting an anomaly in a composite material comprising directing two transmitted electromagnetic wave signals orthogonally polarized with respect to each other from a probe to the composite material, wherein the probe and composite material are positioned for near-field evaluation of the probe. A related apparatus comprising an open-ended square waveguide probe.

Abstract: A grammage measuring apparatus including a dielectric resonator which is arranged only at one side surface of a sample; a shielding container with which the dielectric resonator is substantially covered except for a sample measuring surface; a microwave excitation device which causes the dielectric resonator to generate an electric field vector; a detection device which detects transmission energy or reflection energy by the dielectric resonator; a storage device in which a calibration curve indicating a resonance frequency shift amount for a grammage is stored; and a data processing device which calculates the grammage of a measuring sample from the calibration curve and measurement result of the resonance frequency shift amount of the measuring sample.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: A pulse detection system for expanded time radar, laser and TDR sensors detects specific cycles within bursts of cycles. A sensor transmits and receives short bursts of RF cycles. A transmit pulse detector triggers on a selected cycle of the detected transmit burst and starts a range counter. A receive detector triggers on a selected cycle within a received echo burst to stop the range counter, thereby indicating range. Cycle selection is enabled by an analysis window of time. The detection system can provide accuracies on the order of one picosecond and is well-suited to accurate ranging along an electromagnetic guide wire.

Abstract: A radar level gauge using microwaves for measuring a level of a surface of a product in a container, comprising a microwave unit, processing circuitry connected to said microwave unit, an interface for connecting said radar level gauge externally thereof, and a power management circuitry arranged to provide operating power to said microwave unit and said processing circuitry. The power management circuitry includes a temporary energy store, means for providing said temporary energy store with an intermediate voltage lower than an operating voltage required by said processing circuitry, in order to charge said energy store, and converting means, for converting an output voltage from said temporary energy store up to said operating voltage. According to this design, a sufficient amount of energy can be stored in the temporary energy store, operating at an intermediate voltage lower than the operating voltage of the radar level gauge.

Abstract: A position detecting device finds the position of a specimen arranged in a conductive structure on the basis of microwaves and comprises an electrical circuit for the production and/or reception of the microwaves and a microwave antenna arrangement for emitting and/or receiving the microwaves. Said position detecting device includes a dielectric antenna body with a first pole face and a second pole face for the transmission of microwaves. The antenna body forms a component of the microwave antenna arrangement. The electrical circuit is at least in part arranged on the antenna body.

Abstract: Wet and dry film thickness can be measured non-invasively on structures, such as surfaces associated with vessels, aircraft and buildings, using calibrated microwave sensors. The film is measured by directing microwave energy toward the film. The microwave energy passes through the film and is reflected by a reflective or semi-reflective substrate surface below the film. Properties of the reflected wave are compared with properties of reflected waves that were passed through calibration samples of known thicknesses to determine the unknown thickness of the film. In some embodiments, one or more sensors are maintained at a fixed altitude above the conductive/semi-conductive substrate for measurement, and in other embodiments, one or more sensors are maintained at a fixed altitude above the film.

Abstract: A radar level gauge (RLG) is provided for determining a filling level of a filling material contained in a container by transmitting and receiving elliptically or circularly polarized waves. The RLG comprises: a feeding circuitry for feeding and receiving two essentially orthogonal elliptically polarized waveguide modes, one of the modes for transmission and another mode for reception; an antenna for transmitting the waveguide modes towards the filling material and for receiving reflected signals; and a waveguide to provide signals between said feeding circuitry and the antenna. Further, the feeding circuitry comprises: a microwave generating unit (TX); a microwave receiving unit (RX); at least three feeding probes being at least partly exposed to the interior of the waveguide; and a coupling circuitry for transferring and feeding signals between each feeding probe and the microwave generating unit and/or the microwave receiving unit.

Abstract: An antenna assembly suitable for use with a microwave-based level measurement system mounted on a vessel. The antenna assembly comprises a rod antenna having a mounting member with an integral sealing ring. The antenna is molded from a conductive polymer such as PTFE. The sealing ring is also formed from the same polymer as the antenna. The sealing ring may be formed as an integral component of the mounting member molded from a polymer material or as a separate ring element which is welded or otherwise affixed to the mounting member. The antenna assembly is coupled to the level measurement apparatus using a clamping mechanism. As the clamping mechanism is secured to the mounting member, the sealing ring is compressed and deflected and in the compressed state provides a seal between the level measurement apparatus and the section of antenna extending into the vessel. According to another embodiment, the antenna assembly is adapted for and mounted in a horn antenna.

Abstract: A radar level gauge system is disclosed, having a transmitter for transmitting measuring signals towards the surface of the filling material, a receiver for receiving echo signals from said surface and a fastening structure adapted to secure said transmitter and receiver in a measuring position on a feed-through structure located in an upper boundary of said container. Further, a sealing unit is arranged between said fastening structure and said feed-through, and adapted to provide a pressure seal between the inside and the outside of the container, and in addition, there is provided means for blocking electromagnetic energy, adapted to block net transfer of electromagnetic energy between the inside and the outside of the container through said sealing unit.

Abstract: A body scanning measurement, typing and profiling apparatus and method utilizing microwave energy. Microwaves are used to measure the size and shape of an individual. An array of miniaturized transmitting antennas direct RF energy to a similarly sized array of receiving antennas. Microwaves are directed toward an object, such as a human being, to be measured and the unabsorbed energy of the microwaves transmitted is measured and converted to a signal representative of the size and shape of the object being measured. A computer processor generates vital body measurements and stores such measurements for future use.

Abstract: A method and an apparatus is described to measure at least one physical parameter of a substance such as moisture and salt content. This is done by transmitting a microwave beam through the material to be measured and detect only a reflection of a predetermined polarity of the transmitted waves. To accomplish this a polarizing plate is used so that only cross-polarized microwaves, which pass through the substance are detected and the co-polar reflections from surrounding structures are excluded. The object can either be moving as on a conveyer belt or in a rest position.