Abstract: A quite novel electromagnetic wave source probing device and a method with such a device in which the probing time can be shortened. Magnetic field to time characteristics generated from a subject to be measured are measured in a plurality of positions. Electric field to frequency characteristics generated from the subject to be measured are calculated by use of the plurality of measured magnetic field to time characteristics. Frequency components exceeding a predetermined electric field value are extracted in the calculated electric field to frequency characteristics. Positions where currents having the extracted frequency components exist in the subject to be measured are outputted.

Abstract: In a quasi-hemispherical Fabry-Perot resonator for the non-destructive determination of the surface resistance Rs of electrically conductive thin material films, spherical and planar mirrors are disposed opposite each other in a double shielded cooled resonator space structure supported on individual base plates and the planar mirror, on which a wafer with the thin material film is supported, is mounted on a support arm which extends through the double shield structure. Shield sections through which the support arm extends are supported on pivot arms which are pivotally mounted in the center of the base plates and the shield sections are engaged by the support arm so that they move along with the support arm when the support arm is moved sidewardly for a positioning change of the planar mirror thereby preventing radiation leakage from the resonator space.

Abstract: A system and method for detecting a molecular event in a test sample using a resonant test structure is presented. The method includes providing a resonant test structure having a resonant response associated therewith. Next, a first resonant response of the resonant test structure is obtained when the resonant test structure is electromagnetically coupled to a reference sample, the reference sample having a known composition. A second resonant response is also obtained when the resonant test structure is electromagnetically coupled to the test sample, the test sample having an unknown composition. Subsequently, one or more first electrical parameters, such as the q-factor of the resonator, are derived from the first resonant response. One or more second electrical parameters are similarly derived from the second resonant response. The similarity or difference between the first and second electrical parameters are analyzed to determine the presence or absence of the molecular event in the test sample.

Abstract: Measurement of the permittivity of thin films is facilitated through the use of a short cylindrical metal cavity containing parallel plates between which a specimen to be measured is placed. The use of such parallel plates contained within such a cavity is particularly advantageous when swept frequency measurement methods utilizing frequency ranges from 0 to 20 GHz are employed. A test fixture which is preferred for use in providing such a cavity is disclosed as are methods of using the test fixture.

Abstract: The sample measuring face of a dielectric resonator (20) is placed near a standard sample having a known dielectric constant at a fixed interval D. While appropriately varying the dielectric constant and thickness of the standard sample under the above condition, the variation of the resonance frequency of the dielectric resonator (20) is measured for each varied dielectric constant and thickness to draw a calibration curve of the varied resonance frequency depending on the dielectric constant and thickness. Under the same condition where calibration curve is drawn, the variation of the resonance frequency of the dielectric resonator (20) for a sample having a known thickness is measured. The dielectric constant of the sample is found from the measurement value and the calibration curve. The dielectric constant of not only a sheetlike sample but also a three-dimensional molded article or a liquid sample can be measured easily.

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: There are provided a laminate with an inside layer circuit for use as a multilayer printed circuit board, a method for measuring a circuit impedance of the laminate, and a measuring device that enables a nondestructive impedance measurement accurately. The laminate with the inside layer circuit has a dielectric substrate, a first conductive layer disposed on an upper surface of the dielectric substrate to form a high frequency circuit, a second conductive layer disposed on a lower surface of the dielectric substrate, and a third conductive layer disposed over a first dielectric layer on the upper surface of the dielectric substrate. A test conductor is formed independently of the inside layer circuit within the first conductive layer.

Abstract: A quite novel electromagnetic wave source probing device and a method with such a device in which the probing time can be shortened. Magnetic field to time characteristics generated from a subject to be measured are measured in a plurality of positions. Electric field to frequency characteristics generated from the subject to be measured are calculated by use of the plurality of measured magnetic field to time characteristics. Frequency components exceeding a predetermined electric field value are extracted in the calculated electric field to frequency characteristics. Positions where currents having the extracted frequency components exist in the subject to be measured are outputted.

Abstract: A system and method for detecting a molecular event in a test sample using a resonant test structure is presented. The method includes providing a resonant test structure having a resonant response associated therewith. Next, a first resonant response of the resonant test structure is obtained when the resonant test structure is electromagnetically coupled to a reference sample, the reference sample having a known composition. A second resonant response is also obtained when the resonant test structure is electromagnetically coupled to the test sample, the test sample having an unknown composition. Subsequently, one or more first electrical parameters, such as the q-factor of the resonator, are derived from the first resonant response. One or more second electrical parameters are similarly derived from the second resonant response. The similarity or difference between the first and second electrical parameters are analyzed to determine the presence or absence of the molecular event in the test sample.

Abstract: An instrument and process for measuring moisture content of an article. A microstrip resonator receives a signal from a microwave sweep oscillator. A holder holds the article wherein the article under test is placed over a substrate of the resonator and covers the resonator and provides orientation to the article under test in a desired direction to the sample. A detector receives transmitted as well as reflected signals from a resonator sensor for measurement of Q factor and frequency shift of the resonator. The moisture content of the article is determined by the change in effective permittivity of a cross-section of the miscorstrip.

Abstract: A method for monitoring characteristics of materials includes placing a material in an application zone, measuring a change in at least one property value of the application zone caused by placing the material in the application zone and relating changes in the property value of the application zone caused by the material to at least one characteristic of the material An apparatus for monitoring characteristics of a material includes a measuring device for measuring a property value resulting from applying a frequency signal to the application zone after placing a material in the application zone and a processor for relating changes in the property value caused by placement of the material in the application zone to at least one desired characteristic of the material. The application zone is preferably a resonant cavity.

Abstract: An embodiment of the present invention includes the use of a single connection to measure the resonance frequency of main cells or side cells of a resonant structure, such as a linear accelerator cavity structure. Only one antenna is require to perform both the tasks of exciting a cavity structure and picking up the resonant frequency signal. According to an embodiment of the present invention, a first antenna probe is inserted into the main cells of a linear accelerator cavity structure. The first antenna probe includes an antenna window which may be positioned approximately in the center of a main cell adjacent to a target side cell in order to measure the resonance frequency of a target side cell. All non-target side cells adjacent to the main cell aligned with the window antenna are then shorted. For example, the non-target cells may be shorted by metal surrounding the first antenna probe at locations other than the antenna window. A signal is sent and a resonance frequency is noted.

Abstract: The microwave sensor produces an electrical output signal according to a position or displacement of a movable mechanical part (2), especially a valve needle in an injector valve for injecting fuel into an internal combustion engine. This position or displacement sensor includes a cavity resonator (40,70) provided with walls bounding a cavity (4,7) dimensioned for microwaves of a predetermined frequency and an antenna (8,14) for reception of the microwaves in the cavity. The end (3) of the movable mechanical part (2) protrudes into the cavity. A hybrid evaluating circuit (9) is connected with the antenna, which detects changes in the microwave radiation fed into and coupled out of the cavity, e.g. phase relationships, which depend on the position of the mechanical part (2), so that small position changes in very tight spaces are accurately determined.

Abstract: For determining the quantity of an electrically conductive product contained in a reservoir made of electrically insulating material, having at least one storage cavity: a resonant circuit is formed, including a capacitive arrangement comprising at least part of this reservoir; a processing procedure is defined, consisting of identifying, from a plurality of signals corresponding to different frequencies, the value of a characteristic of this resonant circuit, deriving from this value of the characteristic a measurement of the resistance constituted by the product contained in the reservoir in the said capacitive arrangement and deriving therefrom the instantaneous value of an item of information representing the quantity of product contained in the reservoir from a pre-established correlation law; and a least one determination cycle is effected, consisting of triggering the measurement procedure and the processing procedure, and capturing the instantaneous value of the said item of information.

Abstract: A filter is composed of plural resonators formed on one surface of a dielectric substrate and a ground plane formed on the other surface. A resonant frequency of each resonator is accurately measured individually and independently from other resonators. Other resonators not selected for measurement are all short-circuited or covered with a conductive member to shift their resonant frequency to a region that does not interfere with the resonant frequency of the resonator under measurement. Also, a coupling coefficient of an arbitrary pair of resonators is accurately measured under no interference from other resonators in the similar manner.

Abstract: With the help of the millimeter wave measurement system, the surface impedance is determined by means of one or a plurality of resonators with very high three dimensional resolution when there are relatively large resonator openings in the millimeter wave range. By means of this, structures with measurements of {fraction (1/10)} the resonator openings can be solved with no trouble (FIG. 1).

Abstract: A method and apparatus for measuring the amount of free water contained within a substance includes a waveguide having front and back sides disposed opposite each other. The waveguide defines a chamber for propagating a microwave signal therethrough. The waveguide has an end perpendicular to the front and back sides which forms a short within the chamber. The front and back sides each have an aperture for passing a substance therethrough. A microwave signal in the frequency range of 10-25 gigahertz is directed through the chamber wherein the generated microwave signal is reflected back from the short of the end. The generated and reflected signals form a ratio which is used by a microprocessor along with the measurement from an adjacent sensor that provides a dielectric constant measurement corresponding to the density of the substance in order to determine a weight of the substance compensated for free water.

Abstract: A process for measuring moisture of grains, fruits, nuts and the like (a sample) by connecting the input of a multilayer microstrip hybrid circuit (MMHC) to a pulse generating source, precalibrating the pulse generating source and a time domain reflectometer and connecting the output of the MMHC to a detector. The time domain reflectometer is then calibrated to obtain a characteristic reference reflection and time of propagation through the MMHC is recorded. The sample is placed on the MMHC and a time delay is measured in response to the characteristic reference reflection. The effective permittivity is then calculated based on the parameters of the time domain reflectometer, time delay, reflection coefficient and characteristic impedance of the MMHC. The calculated effective permittivity is then calibrated against moisture.

Abstract: A measuring instrument and method for measuring paint and coating thickness on conductive and poorly conductive substrates. The instrument uses a microwave amplifier, a measurement cavity, and a reference cavity with supporting electronics to measure the apparent changes in the length of the measurement cavity due to the changes in the paint and coating thickness. The measurement cavity resonates when the measurement cavity is set upon the test surface. The oscillating signal is sent through a reference cavity tuned to give the desired filtered response to cover the paint and coating thickness range allowed. The filtered response of the reference cavity is converted to a dc level signal that serves as input to a data acquisition circuit. The data acquisition circuit converts the input signal to digital form so that the calibration method may be used to associate a given response with the corresponding paint and coating thickness.

Abstract: A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables.

Abstract: A method and apparatus for determination of orientation of fibers in a material such as a paper or paperboard web comprised of elongated fibers of high moisture content. The material is subjected to an alternating electric field (E) of the RF or microwave frequency range lying in the plane of the material and the change caused by the presence of the material in the alternating electric field (E) is measured. The direction of the alternating electric field (E) is altered during the measurement, whereby the material need not be rotated with respect to the resonator for the measurement.

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: In a microwave resonator for continuous spectroscopic gas analysis with a microwave cavity having dimensions depending on the operating frequency and a setting for a low quality Q of its base mode and microwave reflectors disposed at its opposite ends and including a round hollow conductor part and a co-axial conductor part separated by a pressure-tight dielectric window, an internal conductor part is axially movably supported in the coaxial conductor part by the microwave reflector at one end of the co-axial conductor part, the other reflector being axially movable for tuning the resonator to a maximal absorption frequency and a by-pass line extends past the co-axial conductor part in the area of the dielectric window and has a short branch connected to the co-axial conductor part and including a restrictor for supplying only a relatively small flow of gas from the bypass line to the conductor part of the microwave resonator.

Abstract: A method of determining a response characteristic of a microwave device includes coupling a microwave resonator to the device, loading the resonator with microwave radiation, monitoring the time decay of power from the resonator, and comparing the monitored time decay with a known characteristic of the time decay of radiation in the microwave resonator when loaded with radiation.

Abstract: The instant invention relates to an apparatus for measuring a powder mass flow in a powder/gas mixture during the conveyance thereof through a feed pipe, the apparatus comprising a velocity measuring device for the powder/gas mixture, a mass measuring device for the powder mass per volume unit, and a calculating device to calculate the powder mass flow based on the velocity measured, the powder mass per volume unit measured, and the dimensions of the feed pipe. The mass measuring device comprises a microwave resonator and means for sensing the resonant frequency and/or the microwave amplitude of the microwave resonator. The microwave resonator is embodied by a coil which is applied on the outside of the feed pipe.

Abstract: An instrument determines one or more physical properties, including dielectric, in a web or other material. A resonant cavity in the instrument resonates at a known band of frequencies. The instrument generates a constant frequency signal within the known band, divides the signal into a measuring signal and a reference signal. With the instrument proximate the web, the measuring signal is passed into the resonant cavity. A first fraction passes through the resonant cavity. incurring a phase shift. A second fraction is reflected from the cavity. The phase shift in the measuring signal is compared to the reference signal, and a first output signal is sent to a controller. The magnitude of the reflected signal is determined, and a second output signal is sent to the controller. Using the first and second output signals, the controller calculates a resultant property value (e.g. moisture content), using the combined values of phase shift and reflected power to cancel out the affect of distance of the e.g.

Abstract: A highly compact, portable, pulsed-molecular-beam Fabry-Perot cavity Fourier transform microwave spectrometer which incorporates ultra-fine Fabry-Perot mirror surface finishes has been developed for trace gas analysis. The mirrors, having a surface finish of less than or equal to 0.25 microns rms, are coated with nickel and then with either gold or silver. In a further embodiment, one or more fixed-tuned Fabry-Perot cavities are incorporated within a single vacuum chamber to monitor one or more chemical species of interest.

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: The ability to be able to identify, distinguish and verify a lock onto harmonic frequency signals in the oil of a hydraulic cylinder using a ratio between consecutively detected harmonics. The identification is useful in providing early and reliable harmonic resonance "lock on" and the ability to "lock on" to a particular order harmonic resonance.

Abstract: A system interface for acquiring data from a microwave conductivity sensor which produces data related to an electrical property of a fluid within a resonant cavity included in the microwave conductivity sensor, the system interface including a memory storing a program; and a computer for executing the program stored in the memory for causing the computer to prompt the microwave conductivity sensor to transmit the data to the computer and to parse the data for particle size information.

Abstract: A lubricating/hydraulic fluid condition monitor in which a coaxial microwave resonator is placed in a fluid conduit to determine changes in the chemical properties and debris concentration is disclosed. Microwave radiation is applied to the resonator for measuring the resonant frequency and resonator Q. An externally powered electric or magnetic field is used to alternately align and misalign debris in the fluid while the resonator properties are being measured. A logic unit automatically generates tables of resonant frequency and Q versus resonator mode and external field strength. This set of tables constitutes a fingerprint of the fluid condition. By matching the fingerprint against a set of fingerprints taken under known conditions, the condition of the fluid is determined.

Abstract: A measuring apparatus and method of a permittivity of a dielectric material employs a cavity and a variable reactance connected to the outside the cavity to measure the permittivity of the dielectric material, in which a power-feeding post is installed within the cavity, the variable reactance for forcibly resonating the cavity is attached to the upper portion of the cavity at the end of the power-feeding post, a network analyzer is connected to the power-feeding post, and the dielectric material specimen to be measured fills up the cavity, so that the length of the variable reactance is adjusted to forcibly resonate the cavity and, at this time, the length of the variable reactance is measured to determine the permittivity of the dielectric material. Thus, unknown permittivity is simply measured while enabling the broadband measurement. A small cavity at a cut-off state is employed to be suitable for measuring the permittivity in a low frequency band.

Abstract: The complex dielectric constant of successive increments of a stream of tobacco particles is indicative of the mass and/or moisture content of the tested increments. Instead of passing along two high-frequency resonators, as disclosed in German patent No. 43 42 505 to Stange, the stream is caused to pass through the inlets and outlets of the housings of two high-frequency resonators which are connected to a microwave generator and transmit high-frequency signals whose amplitudes are indicative of the complex dielectric constants. The signals from the two resonators are processed in a regulating unit wherein a circuit sums up the real and the imaginary parts of the complex dielectric constant.

Abstract: A system including a resonant cavity for measuring in-situ and in real time the Carbon content of the fly ash produced from the combustion process occurring within a pulverized coal-fired steam generator. The resonant cavity basically includes an intelligence section, a transmitting section, a cavity section and a receiving section. When the system including the resonant cavity is so employed the measurements gained therefrom may be utilized either by an operator or as input to a boiler control system or both in order that corrective action may be implemented when such is required.

Abstract: A piston position sensing system in which tabulated resonance width related information is stored in a form correlated with piston travel so that measured resonance width information can be compared with the stored information in determining piston position and compensation for the velocity of the piston is provided by correction for a time difference in serial sensing between the initial and the following extremes of a resonance signal as the piston moves. the compensation is developed from velocity information identified through previous and current processing cycles which assures reliability in detection of the subsequently sensed portion of the resonance signal envelope and enhanced sensitivity and accuracy through automatic application incrementally in a dynamic gain adjustment of the sensing system.

Abstract: A cylindrical microwave cavity 12 has a pinched center 28, 30. Two apertures 28, 30, one in the center. of each face of the cylinder 10, provide access for a gas/powder mixture 124 having a dielectric coefficient depending on its density or some other measurement of interest. The faces 20, 22 of the cylinder 10 are much farther apart at the unpinched periphery, which comprises most of the volume of the cavity. The wider spacing allows an antenna 34 to be placed in the cavity 12, and provides a high Q-factor to maximize the sensitivity of the cavity 12. At the same time, certain resonance modes are greatly affected by a change in the dielectric coefficient of the gas/powder mixture 124 in the pinched portion 28, 30. The density of the powder or any other convenient variable may thus be servoed to any desired value. The powder 124 may be blown through the cavity 10, encased in tube 120 affixed to the cavity 12.

Abstract: A particle component analyzing apparatus and method using a microwave induced plasma to perform element analysis of particles, such as particles existing in a clean room; wherein an aspirator scans a filter to draw particles collected on the filter, and using the microwaves to excite the drawn particles to cause generation of an emission spectrum having a plurality of wavelengths indicative of the elements of the particle, which are measured by a plurality of monochrometers, and converted by an optoelectric converter into electrical signals to identify the different elements in the particle. The invention uses means for obtaining the cube roots of the outputs from the optoelectric converter.

Abstract: The measurement of moisture content in granular materials is ordinarily a difficult measurement to make. The invention of this application sets forth a new method and apparatus for measuring moisture content in a wide variety of materials by means of application of an apparatus that makes measurement of moisture content independent of density of the material measured, and thereby unaffected by ambient conditions. The apparatus also allows the practitioner of this invention to readily and accurately measure moisture content.

Abstract: Systems and methods for monitoring workpiece and workpiece material characteristics using microwave energy are disclosed. A system includes a chamber, including means for generating variable frequency microwave energy; means for positioning a workpiece within the chamber; means for subjecting the workpiece to a plurality of different microwave frequencies; and means for monitoring characteristics of the workpiece. One or more characteristics of a workpiece, or workpiece material, may be monitored by positioning the workpiece within a chamber having means for generating variable frequency microwave energy; subjecting the workpiece to microwave irradiation at a plurality of frequencies; detecting power reflection for each one of the plurality of microwave frequencies to provide power reflection data; and comparing the power reflection data to a predetermined set of power reflection data.

Abstract: Dynamic gain adjustment in hydraulic piston position sensing that continuously accommodates for changes in signal level is provided by attenuating the gain of the sensing system through a comparison of a measured value with a stored value at each piston position.

Abstract: A dielectric resonator apparatus for measuring the parameters of high temperature superconducting thin film is disclosed having improved means for positioning the dielectric and substrates, holding the resonator components in place during use, suppressing undesirable modes, adjusting the magnetic dipole coupling, and coupling to an electrical circuit.

Abstract: A sample and the tip portion of an alternating current scanning tunneling microscope are electrically enclosed within a cavity with electrically conductive walls. The dimensions of the cavity are smaller than the wavelength of a component of the AC signal applied by the probe to the sample so that the output signal detected by the probe from the sample will not be contaminated by resonant effects of the cavity.

Abstract: A microwave spectrometer includes a sensing chamber into which is introduced a gas or constituent to be analyzed. Microwave radiation is introduced into the chamber and any of the chamber resonant frequency, the microwave frequency, and the center frequency of the absorption peak are varied independently. The resultant variation in intensity of the microwave radiation in the chamber is monitored to determine the concentration of the gas within said chamber. The spectrometer may include a frequency measuring and reference system for measuring the resonant frequency of the chamber.

Abstract: A method of measuring the dielectric constant of a sheet-like material is disclosed, the method using a cavity resonator having a transverse slit formed in the intermediate region thereof between the opposite ends for disposing a sample sheet perpendicularly to the direction of the length thereof. The dielectric constant is measured as a function of the difference f.sub.1r -f.sub.r2 between the microwave resonant frequency f.sub.1r of the cavity resonator obtained when the sample is not inserted in the transverse slit and the microwave resonant frequency f.sub.r2 of the cavity resonator obtained when it is inserted in said transverse slit. The resonant frequency f.sub.2r (.beta.) is calculated in the state in which the sample sheet in said transverse slit is rotated through a given angle .beta. with respect to said longitudinal axis from the predetermined angle designated by 0.degree., from the formula approximating the resonance curve in the cavity resonator.

Abstract: An apparatus (102) is adapted to detect the linear extension (position), velocity and acceleration of a hydraulic cylinder (108). The hydraulic cylinder (108) defines a variable length coaxial resonant cavity (112). Under the control of a controller (228), an RF transmitting section (114) and an RF receiving section (116) are used to determine the resonant frequency of the cavity. The resonant frequency of the cavity (112) is determined by comparing a received signal with a threshold and detecting slope intercept conditions.

Abstract: A method for analyzing a gaseous mixture by means of microwave absorption including the steps of: generating microwave energy of at least one frequency known to be absorbed by the component of interest of the gaseous mixture for the presence of one specific gas component; transmitting two beams of the microwave energy simultaneously to a measuring cell and to a reference cell, both cells containing none of the specific gas component of interest; recombining the microwave energy through the matching arms of a waveguide "magic" tee with an "H" arm and an "E" arm; adjusting the phase and amplitude of the reference or measuring beam signals of microwave energy until a null is detected at the "E" arm of the waveguide "magic" tee and all microwave energy is detected at the "H" arm of the microwave tee; allowing the measuring cell to fill with the gaseous mixture to be analyzed; correlating the energy detected at the "H" arm to the concentration of the gaseous component of interest, according to Beer's law.

Abstract: A process for determining a surface resistance to microwave energy of a superconductive film provides a metallic cavity resonator whose resonator cavity is defined by metallic walls, and positioning a superconductive film whose microwave surface resistance is to be measured as at least part of a wall of the cavity. A dielectric body is applied to a surface of the film and microwave energy is coupled to the cavity through an input antenna and microwave energy is coupled out of the cavity by an output antenna at which signals are produced as a measure of the microwave surface resistance of the film.

Abstract: An apparatus and a method for the measurement of the complex dielectric constant of a material by evaluating the amount of detuning introduced by the presence of the material. In order to simplify the circuitry required for measurement and evaluation according to the invention there are provided two rf resonators (8, 8') of the same construction, each of them comprising a dielectric solid state resonator (1, 1') in a case having a first conductive section (2, 2') and a second section (3, 3'), which is permeable for alternating fields. Both the rf resonators are positioned to each other in such a way as to provide a shielding effect by their conductive case sections (2, 2') against mutual interference and to have their sections permeable for electromagnetic fields (3, 3') facing towards the material to be measured.

Abstract: An apparatus (102) is for detecting the linear extension (position), velocity and acceleration of a hydraulic cylinder (108). The hydraulic cylinder (108) defines a variable length coaxial resonant cavity (112). Under the control of a controller (228), an RF transmitting section (114) and an RF receiving section (116) are used to determine the resonant frequency of the cavity. The resonant frequency of the cavity (112) is determined by comparing a received signal with a threshold and detecting slope intercept conditions.

Abstract: A waveguide and pressure barrier for use with devices for measuring fluid parameters of fluids passing in a pipe under high temperature and pressure conditions and utilizing microwave energy for making the measurements, the device including a pair of substantially identical members adapted to be mounted in spaced opposition on the pipe. Each member has an axial bore with a transverse bore for receiving a microwave antenna. The axial bore is substantially filled with a ceramic glass material providing the pressure and temperature barrier.