Abstract: In a quasi-hemispherical Fabri-Perot resonator for the non-destructive determination of the surface resistance Rs of electrically conductive thin material films, spherical and planar mirros 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 method for measuring a capacitance of a passive device region. The passive device region is formed on a substrate having a conductive type different from that of the passive device region. Two bias voltages are applied to two terminals of the passive device region. By measuring the distance between these two terminals and the width of the passive device region, plus the grading coefficients of both area effect and sidewall effect, capacitance induced at both terminals can be derived.

Abstract: A sub sensor for measuring a small area is integrally incorporated in a main sensor for measuring a large area and a part in the vicinity of the edge of a wafer is measured by the sub sensor, while a center of a wafer is measured by the main sensor.

Abstract: Determination of the quantity of consumable product present in a reservoir, for example the quantity of ink present in the reservoir of an inkjet printing device. According to the invention, the movable reservoir can be engaged in the dielectric space of a capacitor consisting of two plates, a signal generator applies a signal to the capacitor and the reservoir is moved, a comparator changes state when a threshold is reached and the distance travelled by the reservoir makes it possible to determine the quantity of product situated therein.

Abstract: A method for measuring axial deviation in a taut-wire alignment system (1) that includes a dynamically grounded resistive wire (2) extending along a longitudinal reference axis and adjacent to elements to be aligned (3). The method comprises applying an AC voltage signal to a measurement electrode provided with a reference electrode, the measurement electrode being arranged in a measurement plane in a holder attached to an element to be aligned (3); carrying out a measurement using a capacitive bridge that includes a first capacitor consisting of the measurement electrode and the wire, as well as a second capacitor, in order to provide a measurement signal representing an axial position of the measurement electrode relative to the taut wire (2) ; and processing the measurement signal to provide data indicating the axial deviation between the element to be aligned (3, 7) and a predetermined alignment position. The method is particularly suitable for aligning elements in linear colliders.

Abstract: A method and apparatus for moving an article relative to and between a pair of distance sensing probes of a thickness measuring apparatus which are spaced apart a known distance D is described. In the method, the article is moved relative to and between the pair of probes in at least one direction in a plane normal to a common measurement axis Ac between the probes. A distance a along the common measurement axis Ac between the first probe and a point on the surface of the article nearest to the first probe of the pair that intersects the common measurement axis Ac is measured. A similar distance b between the second probe and the article is measured.

Abstract: A device and method are provided for determining the thickness of a layer of solid ice, a mixture of ice and water, or a mixture of ice and other liquid, accumulated on the outer surface of an object. First and second total impedance sensors are operated at first and second frequencies. Corresponding first and second AC total impedance measuring circuits are coupled to the first and second sensors to produce output voltages based on the total impedance changes sensed by the sensors. A processor is coupled to the first and second measuring circuits to generate an output value using the measured output voltages. The output value is indicative of the thickness of the ice or ice and water mixture, or ice and other liquid.

Abstract: A surface of the sample is scanned in intermittent contact mode with an the AFM. The probe tip is electrically conductive and is electrically connected to a capacitance sensing circuit. The oscillation of the AFM probe modulates capacitance between probe tip and sample surface. The modulated capacitance is demodulated to yield the capacitance properties of the sample.

Abstract: A distance detector detects a distance between a focal position and a workpiece by use of a capacitance. A sensing electrode forms the capacitance relative to said workpiece. An input signal generator generates an alternating signal or an input signal that is input into the sensing electrode. A signal detector detects an alternating signal or a detection signal that is generated at the sensing electrode and that has a value varied in accordance with the capacitance. A computing unit receives the input signal from the input signal generator and the detection signal from the signal detector. The computing unit extracts a component having the same frequency as a frequency of the input signal from the detection signal. Thus, it computes the extracted component to generate a distance information output representing the distance between the focal position and the workpiece.

Abstract: A distance sensor has a capacitive element in turn having a first capacitor plate which is positioned facing a second capacitor plate whose distance is to be measured. In the case of fingerprinting, the second capacitor plate is defined directly by the skin surface of the finger being printed. The sensor comprises an inverting amplifier, between the input and output of which the capacitive element is connected to form a negative feedback branch. By supplying an electric charge step to the input of the inverting amplifier, a voltage step directly proportional to the distance being measured is obtained at the output.

Abstract: A liquid level detecting circuit is pattern-printed on a board. The liquid level detecting circuit has a pair of discharge elements and an electrostatic capacitance change detecting circuit. One of the discharge elements is grounded, and the other of the discharge elements is connected to a pipetting probe and the electrostatic capacitance change detecting circuit. When an extraneous noise signal such as a noise signal caused by static electricity charged on the surface of a container is input through the pipetting probe while the pipetting probe is being moved toward the container containing a liquid the liquid surface of which is to be detected, the extraneous noise signal is discharged to the ground through the pair of discharge elements to suppress the transmission of the noise signal to be transmitted to the electrostatic capacitance change detecting circuit.

Abstract: A method and apparatus are provided for determining the doping concentration profile of a specimen of semiconductor material. The specimen is positioned between a pair of electrodes, the specimen being disposed on one of the electrodes and being spaced form the other electrode by a nonconductive medium. In one implementation of the invention the nonconductive medium is air. A region of the surface of the specimen is illuminated with a beam of light of wavelengths shorter than that corresponding to the energy gap of the semiconductor material and which is intensity modulated at a predetermined frequency. A variable DC bias voltage is applied between the pair of electrodes, the variable DC bias voltage varying between that corresponding to accumulation and that corresponding to deep depletion for the specimen. The intensity of the light beam is low enough and the speed at which the DC bias voltage is varied is fast enough such that no inversion layer is formed at the surface of the specimen.

Abstract: An apparatus and a method for detecting the presence and position of a wafer upon a semiconductor wafer support pedestal surface. Specifically, a wafer detector comprising a plurality of electrodes on a surface of the wafer support pedestal. The electrodes are coupled to a capacitance measurement circuit that measures the capacitance between the electrodes and generates a signal corresponding to a wafer's presence, location and chucking condition. The wafer's presence completes an electrical circuit between the electrodes, increasing the capacitance between the electrodes. As such, the presence of a wafer, the position of the wafer, and the condition of the wafer, i.e., wafer damage, can be detected upon a wafer support pedestal during wafer processing.

Abstract: Double-emitting and multiple-receiving capacitive measuring device: it comprises a scale equipped with an array of electrodes and a transducer, which moves parallel to and opposite the scale and is equipped with two emitting electrodes and an array of receiving electrodes distributed into N groups. The capacitive coupling between the different electrodes allows the position of the transducer to be determined. A generator emits two emission signals (E0, E1) in phase opposition on the two emitting electrodes of the transducer. The frequency of generated emission signals (E0, E1) depends upon the speed of displacement of the transducer. Processing means determine a dimension with the aid of N signals (R0, R7) received on the receiving electrodes. The more significant bits of the result are provided by a primary counting system using a first algorithm. The less significant bits are provided by a secondary precision system using a second algorithm.

Abstract: Method and apparatus for measuring distance includes a capacitance probe positioned adjacent a rotating member and within the housing of the rotating member such that the distance between the probe and rotating member can be measured. The rotating member and probe co-operate with each other so as to define a capacitor. An oscillator comprising a transmission line is electrically connected to the probe, the resonat frequency value of which is a function of the capacitance of the capacitor. The change in distance between the rotating member and the probe can therefore be measured.

Abstract: An apparatus for measuring magnetic recording head transducer to disc surface spacing and a method of fabricating the same are disclosed. A slider body of a read/write head has first and second rails forming portions of an air bearing surface of the slider body. First and second cavities are formed in the first and second rails of the slider body at the air bearing surface. First and second capacitance plates are positioned within the first and second cavities, respectively, such that a surface of each of the first and second capacitance plates is substantially coplanar with at least portions of the air bearing surface.

Abstract: C-V measurement is first carried out with respect to a target area on a semiconductor wafer using a measuring electrode located over the target area. Parameters used for C-t measurement of the target area (for example, applied voltages Vacc and Vmeas or a recovery time Tr) are then obtained from a C-V characteristic obtained by the C-V measurement. C-t measurement is subsequently carried out with respect to the target area using these parameters.

Abstract: A quasi-electrostatic sensing system surrounds an electrically conductive mass with an electric field, the magnitude of which is sensed at one or more locations to resolve a property of interest concerning the mass. The object intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed mass, whether or not the mass provides a grounding path, and the geometry of the distributed electrodes. Because the response of the field to an object is a complex nonlinear function, adding electrodes can always distinguish among more cases. In other words, each electrode represents an independent weighting of the mass within the field; adding an electrode provides information regarding that mass that is not redundant to the information provided by the other electrodes.

Abstract: A system for detecting a gap of unknown width, the system having an RF signal generator having an output interface that outputs an RF signal and that interfaces with an input portion of a test device that is electromagnetically connected with a first surface of a gap. The system also comprises an RF signal receiver having an input interface that receives an RF signal and that interfaces with an output portion of the test device that is electromagnetically connected with a second surface of a gap. The RF signal receiver generates an electrical output to an output interface when an RF signal is detected. A processor has an input interface that interfaces with the output interface of the RF signal receiver and the processor converts the electrical signal from the receiver into an indication to the user of the presence of a gap in the test device.

Abstract: A electrostatic adhesion tester for thin film conductors. In one embodiment, a device is provided for testing the adhesion strength of a thin film conductor that has been formed upon a substrate. The device includes an adhesion tester that is primarily comprised of a conducting portion. The conducting portion is applied to the thin film conductor so that it does not physically contact the thin film conductor, but leaves a small space there between. A power supply may further be provided for coupling to either the adhesion tester, the thin film conductor, or both in order to create a potential difference between the conducting portion and the thin film conductor. The potential difference creates an electric field between the conducting portion and the thin film conductor that induces stress in the thin film conductor.

Abstract: A system for determining the edge of a continuous web and which compensates for non-uniformity in dielectric response, including thickness is disclosed. The invention comprises first electrode for outputting a signal corresponding to the edge position of a continuous web; and second electrode associated with said first electrode for outputting a second signal corresponding to the thickness of the web, such changes in the output signal of the second electrode are related to the output signal of the first electrode.

Abstract: An object sensing system (10) employs a resonant sensor (20) that receives drive energy coupled from an oscillator (12) operating at a frequency equal or close to the resonant frequency of the resonant sensor. The resonant sensor preferably includes an planar winding (60) that maximizes its distributed inductive and capacitive components, which are sensitive to a proximal conductive, nonconductive, magnetic, or nonmagnetic object (22). The resonant sensor is electrically connected in one leg of a voltage divider that produces a changing output signal voltage in response to resonant frequency changes caused by the object in proximity to the resonant sensor. The signal voltage is amplified, filtered, and processed to extract relevant data indicative of the presence, distance, movement, or proximity of the object.

Abstract: A capacitive measuring device has a scale and a transducer, both provided with an array of electrodes. The position of the transducer with respect to the scale is determined in a processing circuit by evaluating the capacitances formed between the two arrays. These capacitances vary periodically as a function of the relative position of the transducer. The scale electrodes are spaced by a pitch (.lambda.). In order to increase the resolution, the transducer electrodes occupy possible initial positions spaced by an elementary interval (P) which is a submultiple of the pitch (.lambda.). The transducer electrodes are thus divided into N groups according to the initial position which they occupy. In order to compensate for manufacturing imprecisions of periodic type, the succession of transducer electrodes is highly non-periodic. To this end, the set intervals (I.sub.

Abstract: A composite capacitive sensor device for use at least up to 1300.degree. C. and 40 bar, including a coaxial cable comprising a conductive sleeve (10) and an inner conductor (21), which are separated by a first insulator (19), and a probe (1) comprising elements which are all refractory and anticorrosive, which are respectively connected to the end portions of said cable and which comprise a metal housing (2) and an electrode (4) having a flat surface (4a) of larger area than the cross-sectional area of the inner conductor, which elements are separated by a second insulator (9) associated with locking means (3, 16) and are secured by means which are all refractory and anticorrosive (11a-11e).

Abstract: A transducer is disclosed which provides distance or position information about a target relative to the transducer. The transducer has first resistor and a first electrode for forming a first capacitive coupling with a target, a second resistor and a second electrode for forming a second capacitive coupling with the target. Signals of opposite phase or polarity are applied to the respective resistor electrode combinations. By applying signals of opposite phase or polarity, no net signal is applied to the target, thereby avoiding problems with cross talk between adjacent transducers.

Abstract: An electrostatic sensor comprises a ground electrode defining an enclosure having a through-hole for permitting the passage of a body therethrough. A sensor electrode is disposed in the ground electrode. A detecting circuit is disposed in the ground electrode for detecting the passage of the body through the through-hole on the basis of a change in an electrostatic capacitance between the ground electrode and the sensor electrode.

Abstract: A method and apparatus for measuring displacement of one location of a structure, relative to another, spaced apart location.

Abstract: A hydrodynamic bearing is disclosed which includes a shaft and a rotor rotating relative to one another and defining a hydrodynamic bearing in the gap between the relatively rotating parts. Also disclosed is a method for identifying or signaling potential failure of the hydrodynamic bearing. The method for identifying or signaling potential failure includes a capacitance detector for generating a signal representing the capacitance across the gap defining the hydrodynamic bearing, a comparator for comparing the capacitance to an established threshold, and an indicator for providing a signal indicating that operation of the information storage device incorporating the hydrodynamic bearing should continue or that an interruption is likely.

Abstract: A rotatable rotor 41 and a stator 51 located at a predetermined gap between outer circumferential face of the rotor 41 provided with half-cylindrical inner circumferential face are provided. The both ends of the outer circumferential face of the rotor 41 are provided with a step portion 44 to retain a predetermined gap between the opposing faces of the rotor 41 and the stator 51, and a stopper portion 45 to be abutted to both end faces of the stator in the axial direction. A forcing means 61(plate spring) are also provided to force the stator 51 to the rotor 41 so that the inner circumferential face of the stator is abutted at the step portion 44.

Abstract: Apparatus for inspecting the wall thickness of non-round containers includes capacitive sensors which cooperate with oscillator means to provide voltage signals corresponding to container wall thickness to electronic processors which convert the voltage signals to corresponding thickness values and compare them with the desired thickness values. The apparatus subjects the containers to translational movement through the inspection zone while resisting rotational movement. The sensors have at least one sensor element having capacitive sensor portions that are not in the same plane as other capacitive sensor elements or a single sensor element having portions in more than one plane. The sensor elements may be individual sensor elements which are each adapted to inspect different portions of a container or may, in another embodiment, be a single sensor element. The sensors are adapted to be movably mounted so as to maintain efficient contact with non-round containers during inspection.

Abstract: A measuring system measures forces, deformations, and movements. The measuring system comprises at least one LC-circuit, at least one power supply for generating a voltage and a current in the LC-circuits, whereby the frequency, the amplitude, and the phase difference between the current and the voltage in a default situation are known and are furthermore a function of the variable to be measured, as well as at least one detection unit for detecting the frequency and/or the phase difference and/or the amplitude in the LC-circuit. The invention provides therewith a compact, simple and multifunctional measuring system by means of which a reading of the measured value is possible without contact with the subject.

Abstract: A capacitive sensor device for use at least up to 1300.degree. C. and 40 bar, including a coaxial cable comprising a conductive sleeve (10) and at least one inner conductor (21) which are separated by an insulator (19), said cable having an end portion (1) of enlarged diameter forming a probe in which the insulator is an anticorrosive refractory element (9, 29) locked by a first and a second anticorrosive refractory metal protection element (5, 4), welded to the sleeve and to said inner conductor, respectively, which second protection element forms an electrode (4) having a flat surface (4a) of an area larger than the cross-sectional area of the end portion of the inner conductor.

Abstract: An apparatus for medical diagnosis and/or therapy, includes an electromagnetic obstacle sensor. Due to variations of the ambient temperature and humidity and/or due to the hanging of, for example a cloth around the sensors (16,18), drift of the zero point of the control may occur, so that the approaching of an obstacle by a movable part (6) of the apparatus could be incorrectly interpreted by the apparatus. In order to compensate for such drift there is provided a control unit (25) for automatically controlling the output signal V.sub.o of the receiver (27) back to the zero value in the absence of an object in the vicinity of the movable part (6). This control preferably takes place at a comparatively high speed when a cloth or moisture is moved into the vicinity of the sensors, and at a comparatively low speed upon removal of the cloth or the moisture.

Abstract: A method and apparatus for measuring displacement and force transferred through an elastomeric member, such as a suspension bushing (17) as used in a suspension of a motor vehicle, comprises an inner cylinder (26) fixedly connected to a suspension member (23), and an outer cylinder (28) fixedly connected to a chassis member (29). A magnetorheological elastomer (32), having particles embedded therein, is interposed between the inner (26) and outer (28) cylinders, and an electrode (44) is disposed about the inner cylinder (26). When the electrode (44) is energized by electrical current provided from module (18), a preselected electrical state resulting from the dielectric properties of the magnetorheological elastomer (32) varies in a predetermined manner in response to changes in displacement of the elastomeric material (32).

Abstract: The invention is a tester that uses a capacitive probe to test whether components that have multiple power and/or ground pins are correctly oriented relative to the signal-pin tracks on a circuit board. The tester connects, to the signal-pin track to which the pin under test is connected, a test-signal source that supplies to that pin a relatively high-voltage test signal. The tester actively guards the pin by applying to the remaining component pins, through the tester scanning system and its internal resistance, a signal that has the same voltage as that sensed by the capacitive probe. If the component is oriented such that one of the multiple power or ground pins is connected to the signal-pin track to which the test signal is applied, the test signal appears also at the other power or ground pins, since these pins are interconnected by a low impedance path through the component.

Abstract: The present invention relates to a device for the contactless detection of the position of a moving webs. The web has on one side of the web a detector electrode covering its entire width and on the other side in the area of the web edges transmission electrodes fed by an oscillator in phase opposition, so that the capacitive couplings between the transmission electrodes and the detector electrode respond in opposing fashion to deviations of the web from the central position. The signal received by the detector electrode is processed by a current to voltage converter with a very small input impedance so that the potential of the detector electrode remains at zero, and virtually no capacitive displacement currents flow to a screening electrode In this way, the sensitivity of the measurement array is independent of the web width.

Abstract: A sensing system locates an object by sensing the object's effect on electric fields. The object's effect on the mutual capacitance of electrode pairs varies according to the distance between the object and the electrodes. A single electrode pair can sense the distance from the object to the electrodes. Multiple electrode pairs can more precisely locate the object in one or more dimensions.

Abstract: This invention provides a device for capacitively measuring the distance to an object, which comprises an electrode that will couple capacitively with the object, a shield that surrounds the electrode and is electrically isolated from the electrode by means of insulation, and a layer of insulation that surrounds the shield, wherein the insulation between the electrode and the shield, and the insulation that surrounds the shield, are formed by deposition.This invention further provides a method for measuring the distance to a solid object, which comprises forming an electrode that will capacitively couple with the object, depositing a layer of insulation over at least part of the electrode so that the insulation surrounds the electrode, depositing a layer of metal over the insulation to form a shield, and depositing a second layer of insulation over the shield.

Abstract: A radial position sensor includes four capacitive electrodes oriented about a shaft, arranged in two diametrically opposite pairs. Sensor circuitry generates an output signal in proportion to the capacitance between the electrodes and the shaft; the capacitance between an electrode and the shaft increases as the shaft approaches the electrode and decreases as the shaft recedes from the electrode. The sensor circuitry applies an alternating voltage to one electrode of a pair and a 180 degree out of phase alternating voltage to the other electrode of the pair. The electrical responses of the two electrodes to their respective input signals are summed to form a radial deviation signal which is relatively free from the alternating voltage and accurately represents the position of the shaft relative to the electrodes of the pair.

Abstract: In a circuit for use with a micromachined device having a movable mass that forms an inner electrode of a differential capacitor, oppositely phased square waves are applied to two outer electrodes of the differential capacitor. A reset voltage is applied to the inner electrode synchronously with the square waves to stabilize and control the potential on the inner electrode. The signal on the inner electrode is demodulated by sampling during a first half of the square wave and a second half of the square wave between applications of the reset pulse to obtain a voltage that does not contain noise due to the reset switch.

Abstract: A ratiometric circuit (40) includes a differential capacitive sensor (42) for sensing a change in capacitance, a differential capacitive detector (46) operatively connected to the differential capacitive sensor for detecting a change in the capacitance of the differential capacitve sensor, an error voltage generator (48) operatively connected to the differential capacitve detector for generating a corrective voltage in response to the detected change in capacitance, and a bias circuit (50) operatively connected to the differential capacitive sensor for generating a bias voltage inversely proportional to and independent of a supply voltage for maintaining the ratiometricity between an output voltage of the differential capacitive sensor and the supply voltage.

Abstract: A method and apparatus for synthesizing spatial waveforms in electronic position encoders allows the position of a composite spatial waveform applied to an electronic position transducer to be incremented by amounts less than the pitch of the electrodes of the electronic position transducer. The position of the composite spatial waveform is adjusted by applying several individual spatial waveforms to the electronic position transducer during a position measurement. The position of one or more individual spatial waveforms is altered by increments of the electrode pitch. As a result, a position of the composite spatial waveform resulting from the individual spatial waveforms is the average position of the individual spatial waveforms. In one embodiment, the composite spatial waveform is applied to the transmitter electrodes of an electronic position transducer. The position of the composite spatial waveform is adjusted so that the voltage from the electronic position transducer is minimized.

Abstract: A capacitive type proximity sensor having improved range and sensitivity between a surface of arbitrary shape and an intruding object in the vicinity of the surface having one or more outer conductors on the surface which serve as capacitive sensing elements shaped to conform to the underlying surface of a machine. Each sensing element is backed by a reflector driven at the same voltage and in phase with the corresponding capacitive sensing element. Each reflector, in turn, serves to reflect the electric field lines of the capacitive sensing element away from the surface of the machine on which the sensor is mounted so as to enhance the component constituted by the capacitance between the sensing element and an intruding object as a fraction of the total capacitance between the sensing element and ground.

Abstract: The measuring device of the invention uses a capacitor polarized by a continuous voltage and conditioned by a continuous charge amplifier, this charge amplifier having a high-band filter structure, preferably of the second order. The technology of the capacitor and the linking cable is coaxial. The tuning of the chain measurement is effected theoretically without needing standardization.

Abstract: A method and apparatus for monitoring thermal processing of a workpiece using a sensor electrode which can be positioned relative to the workpiece and to which an alternating electric signal is applied in order to determine a measured capacitance (C.sub.meas) present between the sensor electrode and workpiece by evaluating a change in the alternating signal as a consequence of the measured capacitance (C.sub.meas). A measured capacitance frequency distribution is formed from a number of determined measured capacitances (C.sub.meas). The measured distribution is compared with a reference distribution. If a deviation is present between the two distributions, process parameters can be appropriately readjusted. It is preferable to use a laser beam for processing the workpiece.

Abstract: A rotary encoder 10 is composed of a halfway cylindrical stator 11 and a cylindrical rotor 12. The rotor 12 is disposed coaxial with the stator 11 with a predetermined gap. Plural transmitting electrodes 13 with spiral patterns and receiving electrode 14 with a rectangular pattern are formed on the inner surface of the stator 12. The transmitting electrodes 13 and receiving electrode 14 are formed of a FPC substrate 17 with lead lines 15, 16. On the outer surface of the rotor 12, coupling electrode 18 are formed with a spiral pattern so as to be capacitively coupled to the transmitting electrodes 13 and receiving electrode 14. FIG.

Abstract: The fast sampling method for taking a position measurement with an electronic measurement system incorporating a capacitive position transducer of this invention allows such capacitive position transducers to be used in contaminant filled environments, such as on a shop floor or in the outdoors. By sampling the output signals within 25 ns-35 ns from when the input signals were applied to the capacitive position transducer, the adverse effects of resistive contamination can be avoided.

Abstract: A computer-based method and apparatus for fastener hole inspection including a capacitive probe with a plurality of sensor elements, means for grounding the faster hole, and an electronics unit electrically connected to the probe for sequencially charging one of the plurality of sensor elements while applying a guard potential to the remaining sensor elements and adjacent electrical components to eliminate residual capactitances. A profile of the fastener hole is generated by evaluating, through a series resistor, the discharge waveforms of the plurality of sensor elements by converting the capacitance measurements obtained to distance measurements. A centering algorithm is employed to compensate for malalignment of the capacitive probe in the fastener hole.

Abstract: Any shape lead formed on various types of drum may be measured without employing an exclusively-used profiling plane by a lead shape measuring apparatus. The lead shape measuring apparatus includes a shape measuring unit for measuring the shape of a lead formed on a drum used in a VTR while a theoretical value suitable for this lead shape is selected based on the type of drum.

Abstract: A sensor system is operable for detecting the presence of water in an oil emulsion inside the lower gear unit of a marine engine, and for providing an alarm signal when the presence of water is detected within the gear unit. The sensor system includes a ring oscillator circuit and a symmetrical array of passive input probes which are disposed in the oil/water emulsion inside the oil chamber. Each of the passive input probes is electrically connected to the ring oscillator circuit wherein the probes function as fixed capacitors for measuring the electrical characteristics of the emulsion. When a voltage is applied to the oscillator circuit, the oscillator circuit generates an oscillating signal that circulates at a frequency which varies according to the dielectric-properties of the liquid emulsion. When water is introduced into the chamber, the water is emulsified with the oil thereby changing the electrical characteristics of the oil.