Abstract: An electrical path or angle sensor comprises a first, stationary contact segment, a plurality of stationary, second contact segments arranged one behind the other and separated from one another by dividing gaps, these second contact segments being connected to circuit elements, a sliding contact movable in a predetermined direction of movement and displaceable over the contact segments and the dividing gaps dependent on the path or angle, as well as contact tongues formed on the sliding contact and movable therewith, these tongues being aligned with their contact-making points in a contact line and when the sliding contact is moved connecting the first contact segment each time with at least one of the second contact segments in an electrically conductive manner by this line.

Abstract: An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil, is disclosed, together with a process of measuring the critical current of a superconductive material, e.g., a clad superconductive material, by placing a superconductive material into the vicinity of the conductive coil of such an apparatus, cooling the superconductive material to a preselected temperature, passing a low amplitude alternating current through the coil, the alternating current capable of generating a magnetic field sufficient to penetrate, e.g.

Abstract: An apparatus for observing a superconductive phenomenon is disclosed. In the apparatus, a cooling unit cools a superconductor having a threshold temperature at which the superconductor changes from the normal conductive phase to the superconductive phase, and a magnetic field is applied thereto. A current is supplied to the superconductor, and there are clearly observed a phenomenon on which an electric resistance thereof becomes zero at a threshold temperature thereof, a phenomenon on which the superconductor changes from the normal conductive phase to the superconductive phase at a threshold current to be supplied thereto, and a phenomenon on which the super conductor changes from the normal conductive phase to the superconductive phase at a threshold magnetic field to be applied thereto.

Abstract: To measure the gaps between fuel rods in a fuel assembly, a feeler gauge is provided with a pair of resilient arms having elongated electrical resistance strips carried by their confronting surfaces and extending from terminations adjacent the free ends of the arms through a contact point of electrical inter-engagement. The strip terminations are wired into a metering circuit including a current source and an ammeter. When the arm free ends are positioned in a rod gap, the position of the contact point relative to the strip terminations determines the magnitude of resistance included in the metering circuit, and the meter registers the gap dimension.

Abstract: An apparatus for observing a superconductive phenomenon is disclosed. In the apparatus, a cooling unit cools a superconductor having a threshold temperature at which the superconductor changes from the normal conductive phase to the superconductive phase, and a magnetic field is applied thereto. A current is supplied to the superconductor, and there are clearly observed a phenomenon on which an electric resistance thereof becomes zero at a threshold temperature thereof, a phenomenon on which the superconductor changes from the normal conductive phase to the superconductive phase at a threshold current to be supplied thereto, and a phenomenon on which the superconductor changes from the normal conductive phase to the superconductive phase at a threshold magnetic field to be applied thereto.

Abstract: Weak links in superconductors are detected by observing the effect of magnetic field modulation on the microwave resistance of superconductors. The phase detected response to the magnetic modulation can show a peak at T.sub.c. The presence of peak(s) at temperatures below T.sub.c indicates the presence of weak links in the superconductor.

Abstract: A head with a pick-up coil is attached to a supporter so that the head is freely movable along the direction perpendicular to the surface of a superconductor. Fluid spouted from the spout hole of the head maintains the height (gap space) of the head from the surface. The head is firmly fixed to the supporter in the direction along the surface. Since the relative position of the head in the direction along the surface of the superconductor is changable by drive means for moving the superconductor or the head, the distribution of the magnetic flux which is trapped in the superconductor is measured by scanning the surface of the superconductor with pick-up coil.

Abstract: Changes in underwater sediment level in a marine environment are monitored electronically using a probe embedded in the sediment. The probe includes an electrical current source to generate an electric field extending across the sediment interface. Voltage measurements are taken at at least three sensors on the probe whose positions are known relative to the current source. The height of the sediment interface relative to the current source can then be calculated, and logged, and changes in sediment level can be monitored. The conductivities of the sediment and seawater can also be calculated by taking additional voltage measurements.

Abstract: A superconducting wire is produced by the surrounding of a superconductive material core with an intermediate compressible insulating layer and an outer malleable layer and then drawing said composite structure through a series of dies to reduce the diameter of the wire on the order of 400 to 10,000 times or by reducing the superconductive core material to the desired wire size by passing it through a series of dies to reduce the diameter of the wire on the order of 400 to 10,000 times and then coating the wire with a noncompressible insulating layer and then placing an outer malleable layer over the insulated wire and drawing this through dies to snuggly fit the outer layer onto the insulated wire. This wire's superconducting characteristics are not intended for carrying high levels of currents so the reduction of the available current carrying cross section by the introduction of the insulating layer is not of concern in the applications for the wire.

Abstract: The resistivity of particulate matter in a gas stream, such as a combustion gas stream produced in a coal-fired power plant, is measured by collecting a sample of the particulate on the surface of a porous ceramic cylinder, either with or without an applied collection voltage, and then determining the resistance of the sample with a compound measurement electrode having multiple conductors. The reference electrode and the measurement electrode are spirally wound on the ceramic cylinder in an interdigitated manner, so that the two are laterally adjacent down the length of the cylinder. The pressure within the cylinder is controllable, with a pressure below atmospheric being applied to draw the particulate to the suface and ascertain when a sufficient sample for measurement is present, and a pressure above atmospheric being applied to blow away the sample after the measurement is completed, thereby preparing the instrument for the taking of another sample.

Abstract: The present invention provides a passive superconducting sensor for quench detection in a superconducting coil. The sensor consists of a first circuit electrically connected to two voltage taps of a superconducting coil. The first circuit uses nonsuperconducting components and preferably contains a resistive element. The first circuit is magnetically coupled to a second circuit by a hybrid transformer. The second circuit is superconducting and contains a readout coil and preferably a second hybrid transformer. The second hybrid transformer is magnetically coupled to a sense coil which detects flux changes in the superconducting coil. The readout coil is coupled to a readout device which measures changes in the current through the readout coil. The current in the readout coil can be made a function only of the resistance of the superconducting coil between the voltage turns and thus can be used to detect a quench.

Abstract: Disclosed is a container holding a partially conductive ionic fluid with a flexible tactile surface covering the fluid and sealing the container. Along the bottom of the container a series of parallel conductors are located with the farthest spaced apart conductors being connected to a voltage source. Measurements of changes in voltages between individual pairs of conductors will provide an indication of any localized deformation of the flexible tactile surface. Such a tactile sensor can be utilized in any device where an electrical output is desired which is indicative of the surface or surface characteristics of the object to be contacted.

Abstract: A method for measuring the width and profile of structures in a semiconductor wafer comprises the step of constructing test structures on the wafer shaped to function as moats for confining electrically conductive liquid. The moats have an elongated shape. By measuring the electrical resistance exhibited by the liquid within the moat, the dimensions of the moat and, thus, the other structures on the wafer can be measured. In an alternative embodiment, the conductive liquid is used to facilitate electrical contact to the various structures formed in the wafer.

Abstract: Apparatus for determining the electrical characteristics of a superconductive material in a range of microwave frequencies and in a range of cryogenic temperatures has the material incorporated within a resonant cavity mounted on a cold finger for maintaining the material at a predetermined temperature. A pair of test waveguides extend oppositely of the cavity and terminate in separable waveguide junctions for passage of microwave energy to measure the microwave characteristics of the cavity as affected by the superconductive material. The cavity and test waveguides are enclosed in a vacuum chamber from which the cold finger extends for connection to controlled temperature cryogenic cooling equipment. The chamber also contains a plurality of calibration waveguides which extend parallel to the test waveguides, each calibration waveguide terminating oppositely in separable junctions.

Abstract: A method for measuring the width of structures in a semiconductor wafer comprises the step of constructing test structures on the wafer shaped to function as moats for confining electrically conductive liquid. The moats have an elongated shape. By measuring the electrical resistance exhibited by the liquid within the moat, the dimensions of the moat and, thus, the other structures on the wafer can be measured.

Abstract: A linear displacement transducer comprises a winding, a magnetic core which is linearly displaceable relatively to the winding, and a source for energizing the winding with a constant RMS alternating current at a frequency sufficiently high for the resistive losses in the magnetic core to cause the voltage across the winding to vary substantially linearly relative to the linear displacement of the magnetic core. The frequency may, for example, be in the range 10 to 20 kHz, and a temperature sensing winding may be associated with the winding to enable the output from the transducer to be compensated for temperature changes, or the winding may be used in time-division multiplex for this purpose.

Abstract: A bumper for impact detection with an object is disclosed. An electrically conductive member has a compressible, electrically conductive material mounted thereto. An insulator formed of mesh material is sandwiched between the electrically conductive member and the electrically conductive material for electrically insulating the member and the material when the member is in a non-compressed state and to provide electrical conduction between the member and the material when the conductive material is in a compressed state.

Abstract: The position sensor of the present invention includes a pair of elongated conducting members disposed in a parallel arrangement and a conducting metallic ball or mercury drop freely movable following the pair of elongated conducting members while maintaining a simultaneous contact with the pair of elongated conducting members, which combination provides two electric circuits respectively including a first circuit including a first poriton of the two elongated conducting members and the contact provided by the metallic ball or mercury drop, and a second electric circuit including the second portion of the two elongated conducting members and the same contact, wherein the metallic ball or mercury drop divides the combination of the two elongated conducting members into the first and second portions.

Abstract: The sensor comprises a body defining a closed chamber which is partially filled with electrically conductive liquid. A main electrode and first and second auxiliary electrodes extend within the chamber in such a way that a variation in the inclination of the body from a predetermined position causes a corresponding variation in the electrical resistance between each auxiliary electrode and the main electrode. The monitoring circuit for the sensor comprises a generator which applies square-wave signals to the auxiliary electrodes in counterphase, and a detector/amplifier which is synchronized with the generator and samples the signal taken from the main electrode in the sensor.

Abstract: A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the "measured length" of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor.

Abstract: Weak links in electrically continuous superconductors are detected by observing the effect of magnetic field modulation on the dc resistance of superconductors. The phase detected response to the magnetic modulation shows a peak at T.sub.c. The presence of a second peak at temperatures below T.sub.c, and concomitantly the appearance of a tail on the low temperature end of the dc resistance vs temperature curve indicates the presence of weak links in the superconductor.

Abstract: A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

Abstract: A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

Abstract: The invention relates to a method and apparatus to detect the superconductive state by measuring the change in the resistance of a sample. A dc magnetic field is imposed on the sample while the temperature is swept. The strength of the magnetic field is held below the critical value and is frequency modulated by the application of an ac field in such a way that total magnetic field is always positive. The resistance of the sample is measured incrementally as the temperature is swept and is phase detected at the modulation frequency. According to this embodiment, only magnetic field dependent changes demonstrating a precipitous drop in resistance identify a composition as superconductive.

Abstract: A semiconductor integrated circuit for sensing a physico-chemical property of an ambient includes a pair of semiconductor devices (Q1, Q2) having a similar geometric and physical structure, one device (Q1) being sensitive to the property, the other being insensitive to the property, together with a differential amplifier (A1, A2, A3, A4, A5) having feedback connection to one of the pair of semiconductor devices.

Abstract: A method and apparatus for detecting hydrogen sulfide with improved longevity. The hydrogen sulfide detector includes a semiconductor comprised of indium oxide attached to an inert substrate. A noncontinuous film of an inert conductor such as gold is deposited on the semiconductor and means are provided for measuring a change in conductance of the semiconductor. In one embodiment tin oxide may be substituted for indium oxide. Also a method of detecting hydrogen sulfide including the steps of: coating a semiconductor with a noncontinuous film of an inert conductor, maintaining the temperature of the semiconductor in a range sufficient to insure proper response and recovery actions of the semiconductor when it is exposed to hydrogen sulfide; and exposing the coated semiconductor to a gas containing hydrogen sulfide while measuring the change in conductance in the semiconductor. The semiconductor may be made up of tin oxide or indium oxide and the inert semiconductor may be gold.

Abstract: An electrical circuitry for use in the measurement of the activity of ions in an electrolyte solution carried out by the use of an ion-sensitive field-effect transistor transducer having a gate or ion sensitive layer, a source and a drain. The measurement is carried out by adjusting the drain current flowing through the field-effect transistor to a predetermined value such that the temperature dependency of the electroconductivity of the channel of the transistor becomes equal to the sum of the temperature dependency of the potential at an interface between a reference electrode and the electrolyte solution and the temperature dependency of the potential at an interface between the ion-sensitive layer and the electrolyte solution.