Abstract: In a magnetoresistive sensor employing a single stage comparator circuit for signal threshold detection, an hysteresis deadband is established substantially proportional to signal amplitude. The sensor includes a transducer comprising at least one magnetoresistive element and an hysteresis circuit also including the at least one magnetoresistive element.

Abstract: A device for sensing projectile velocity in an underwater environment is provided. The device includes a plurality of evenly spaced voltage coil members positioned in the path of a projectile. Each voltage coil member includes a support frame having an opening therein and a magnetic coil mounted on the support frame, and a sensing member connected to each support frame. The sensing member includes means for outputting a signal responsive to passage of the projectile through the voltage coil member, and a logic arrangement for determining a difference between passage of the projectile between adjacent ones of said plurality of voltage coil members throughout the run thereof, thereby determining a velocity of the projectile.

Abstract: A system and method use magnetic field sensing to detect underground objects for strike avoidance. The system detects magnetic field components for both passive distortions in the magnetic field indicative of a ferromagnetic object and active magnetic fields that are impressed on an object by a signal generator. A detection module has a magnetic sensor assembly that detects the magnetic field components. The magnetic field component data is transferred through a multiplexer to an analog/digital converter to a processor. Pitch angle data from a pitch sensor and roll angle data from a roll sensor also may be transferred to the processor. The data is processed by the processor to determine the orientation of the detection module with respect to the object. The detection module may be installed in an underground boring tool or a trenching assembly.

Abstract: A system for sensing projectile velocity and position having a plurality of support members positioned in a path of said projectile. Each support member has an aperture with a resistive trace supported in the aperture. The resistive trace can be separated by the projectile's passage. A sensing circuit is joined to each resistive trace and provides a signal indicating separation of the resistive trace. This signal is provided to a logic circuit which provides a single signal indicating separation of each said resistive trace. A data acquisition system provides an output indicating said projectile velocity and position with respect to time.

Abstract: In summary, preferred embodiments disclose a system, method, and program for generating and displaying disk drive performance data. A center stripe of one sector of one track on a recordable surface is read. An indication is made indicating whether the read operation to the center of the sector succeeded. Each offset stripe from the center of the track in the sector within the track is read and indication is made as to whether each read operation to each offset stripe succeeded. Output in human observable format is generated indicating whether each offset stripe and the center stripe for the sector and track were read successfully or could not be read.

Abstract: A method and apparatus for determining the size or diameter of boreholes extending to a wide range of dimensions and/or the resistivity of the surrounding earth formations utilizing a well tool disposed in the borehole. The method involves generating model data representative of the well tool responses to different borehole diameters contrasted with formation and borehole fluid resistivity values, determining the borehole fluid resistivity, transmitting electromagnetic energy into the formation, measuring the energy shed back into the borehole at arbitrary sensor stations on the tool and generating resistivity signal data associated with the measured energy, and matching the signal data and the fluid resistivity against the modeled response data to determine the borehole caliper and/or formation resistivity. The apparatus forms part of a system for calculating a borehole caliper and/or the surrounding formation resistivity.

Abstract: A strongly miniaturizable magnetic field sensor is based on four spin tunnel junctions, together forming a Wheatstone bridge. The magnetically sensitive electrode functions as well as a laminated flux concentrator, resulting in a low noise single domain configuration, and allowing for magnetization flipping for offset correction. The very simple design also allows easy definition of the fixed magnetization direction of the counter electrode. Very high output voltage combined with very low power.

Abstract: A motor unit is provided for operating an internal hub transmission, and a speed sensor is mounted to the motor unit for detecting a speed signal external to the motor unit. Since the speed sensor is mounted to the motor unit, the position of the speed sensor can be securely fixed on the bicycle. Also, the wire for the speed sensor may be integrated into the wiring harness for the motor, thus eliminating the requirement of a separate wire route along the bicycle.

Abstract: A traceable push rod having a predetermined length comprising an inner layer, an intermediate layer and an outer layer. The inner layer characterized as being electrically conductive. The inner layer preferably made of copper or copper alloy. The intermediate layer characterized as being electrically insulative. The intermediate layer preferably at least partially made of fiber glass. The third layer characterized as being water proof. The third layer preferably made of plastic. The traceable push rod further having a first end and a second end. The first end having at least one sonde receiving terminal for removably receiving a sonde. The second end adapted for electrical communication with an electrical power source such as a battery or transmitter. The electrical power source adapted to provide an electric current to the inner layer and/or the sonde.

Abstract: A borehole tool for logging resistivity of geologic formations, having at least two inner transmitters surrounded by at least two outer receivers. Each transmitter is sequentially excited, and measurements are taken at each of the receivers. The phase differences between these received signals are determined, once for each transmitter, and the two values are averaged to estimate the resistivity value of the surrounding formations. More than two receivers can be used. An azimuthal receiver array is also used to identify boundary transitions.

Abstract: A magnetostrictive linear position sensor produces a signal which is a time period. It is sometimes required to measure this time period and produce an output in another form which accurately represents the time period. The final output may be a voltage, current, frequency, digital or other signal format. A time period is commonly measured using a clock and a counter. The resolution is limited by the frequency of the clock. An upper limit for the clock frequency is usually set based on power consumption or other circuit constraint. A method and apparatus is disclosed for improving the resolution of a time interval using low power and for providing a response after one time period without averaging.

Abstract: The invention relates to a method and an apparatus for measuring properties of a moving web, a sensor (1) being arranged on a first side of the moving web (7), the sensor comprising a differential coil (3), which comprises at least two coils, and a reference plate (4). A sensor plate (6) is arranged on a second side of the moving web (7). Electric current is used to induce a voltage to the differential coil (3). The voltage of the differential coil (3) varies as the web (7) changes the effect caused by the sensor plate (6) to the differential coil. The properties of the web (7) are determined by measuring the voltage of the differential coil (3).

Abstract: A method and apparatus are provided for efficiently testing magnetic media in which a read level test is performed using an approximation for an average signal level in determining a test threshold and while reading data and testing against the approximate average read signal level, the data signal level is averaged to determine the real average read signal and this value is then used to adjust the results of the comparisons performed against the approximate average read level.

Abstract: The present invention relates to a device for measuring a current in a magnetic field which includes a glass article wherein the glass may be an oxyfluoride glass or a bismuth oxide glass having a photoelastic coefficient of from about −0.2 to 0.2 at 546 nm. Further, the present invention relates to a method of measuring currents.

Abstract: A method and a measuring device for determining the spatial distribution of a magnetic field vector. At least a pair of sensor elements is provided. Each sensor element measures a component of the magnetic field vector. The sensor elements are aligned in a parallel, spaced-apart relationship along an axis parallel to the measured components.

Abstract: In accordance with the teachings of the present invention, a method is provided for analyzing RFT data from a data file. The method includes parsing the data file into pipe lengths, calculating a phase profile for the data points within each pipe length, locating potential defects in the pipe length using the phase profiles, determining for each defect a total equivalent phase shift as a combination of a circumferential equivalent phase shift and a non-circumferential equivalent phase shift, and using the total equivalent phase shift to analyze the defect.

Abstract: A position detector includes an outer tube of having a magnetostrictive wire disposed therein. An electric circuit is mounted completely within the outer tube and is electrically connected to a pickup coupled to the magnetostrictive wire. A multi-pin connector is mounted at one end of the outer tube for coupling conductors extending from the circuit in the outer tube to external conductors. In an alternative embodiment, the position detector includes a threaded adapter threadingly mountable within an end wall of a pressurized fluid operated cylinder. Conductors extend from the circuit in the outer tube through the adapter to an external connector.

Abstract: A method of determining a time-dependent gradient of a shock wave in a percussion or subjected to a percussion load ferromagnetic element and including subjecting the ferromagnetic element to action of a magnetic flux, providing a voltage measuring instrument associated with the ferromagnetic element for determining a change of a magnetic flux velocity, which is determined as a change in a measuring voltage, during a percussion action, and determining the gradient of the shock wave by additive superimposition of the measuring voltage; and a device for effecting the method.

Abstract: A guide device for linear guidance of elongated objects, particularly for positioning wires passing a nondestructive eddy current test device, can be the inlet nozzle or outlet nozzle, and has a brush arrangement integrated into a guide sleeve. The brush arrangement damps vibration of the wires or other elongated objects transiting the test device. A wire guided by the guide device is protected at its surface and subjected to little or no transverse vibration in the vicinity of the test probe of the test device, resulting in improved measurement accuracy.

Abstract: An electronic circuit for automatically compensating for errors in the output signal of a displacement sensor. The electronic circuitry includes an analog to digital converter for converting an analog output signal from a linear displacement type sensor. The digital output signal from the sensor is processed by a microcontroller which automatically compensates for errors in the output signal. Ideal values, stored in an electronic memory, are used for compensation.