Abstract: This invention pertains to a method and apparatus for determining the thickness of a ferromagnetic or paramagnetic material when only one side of the material is accessible. In one embodiment, the invention provides a method for engaging a constant signal with the ferromagnetic material for inducing a changed signal, generating a stepped saturation signal over a range of currents for engagement with the ferromagnetic material, detecting the changed signal as the saturation signal is varied over the range of currents, determining the relationship between the changed signal and the stepped saturation signal, and evaluating the thickness of the material based upon the relationship between the changed signal and the stepped saturation signal.

Abstract: An apparatus and method for inspecting contours formed along a predetermined region of a surface on a workpiece formed of an electrically conductive material using eddy current. A probe includes a longitudinal axis and is moveable along a path of travel with respect to the predetermined region to be inspected on a workpiece. At least two coils are spaced longitudinally from one another and supported by the probe to be electrically excited with a predetermined frequency and amplitude during movement of the probe along the path. Sensors are provided for measuring the excitation voltage of each coil as eddy currents are induced in the electrically conductive material of the workpiece by the coils supported on the probe moving along the path of travel with respect to the workpiece.

Abstract: A system and method for gathering and analyzing data captured from one or more remote sensing units positioned in the field. Remote sensing units preferably utilize optical sensors. Power to sensing unit components is preferably selectively controlled to reduce power consumption. Remote sensing units according to the invention can be used for a variety of purposes, including water quality or electrical power monitoring, and data from such sensing units is preferably transmitted to a secure host terminal via a communications link. The host terminal preferably formats, analyzes, and stores the data for customer review and retrieval. If alarm conditions exist that require immediate customer notification, such notification can be sent to a customer via one or more telecommunications means. Through the use of the present invention, businesses can shift from a reactive to a proactive mode of monitoring and operation.

Abstract: The present invention provides a position sensor which is suitable for use in a piston and cylinder assembly. The position sensor includes a movable field modifying member which is operable to vary the inductance of a sensor winding, whereby the position of the field modifying member relative to the sensor winding can be determined by monitoring the inductance of the sensor winding. The position sensor also includes a compensation winding which is arranged to have a common coupling with the field modifying member whereby a signal output from the compensation winding can be used to compensate for variations in the signal level output by the sensor winding caused by, for example, temperature variations of the system.

Abstract: A non-contact displacement detecting device including a permanent magnet fixed with a rotational member, a sensor portion fixed with a non-rotational member, and the sensor portion detects a displacement of a detected object connected with the shaft. The non-contact displacement detecting device includes a housing for supporting the rotational member rotatably and restricting one movement of the rotational member in an axial direction, and a holder for contacting with the rotational member at a plurality of contact points and restricting another movement of the rotational member in the axial direction. Thereby, the movement of the rotational member in the axial direction is restricted by the holder and the housing.

Abstract: According to the invention there is provided a pulse signal generator comprising a plurality of magnetic elements arranged in an imaginable plane and capable of producing large Barkhausen jumps; a first unit for generating a magnetic field, which is changed by the object to be detected to cause the magnetic elements to produce the large Barkhausen jumps, the first unit consisting of a pair of magnet/yoke combinations provided on opposite sides of said imaginable plane such that their poles are oriented in opposite directions, forming a detecting area at an end thereof; a second unit for detecting the large Barkhausen jumps to produce corresponding pulse signals; and first and second adjusting yokes being movable on one of the magnet/yoke combinations along one of the magnetic elements and on the other of the magnet/yoke combinations along the other of said magnetic elements, respectively.

Abstract: In a superconductive quantum interference element comprising Josephson joints, a washer coil and a detecting coil constituting a superconductive loop and a feedback modulation coil, to provide a superconductive quantum interference element capable of promoting spatial resolution by preventing an effective detection area of the detecting coil from enlarging even when a width of a superconductive wiring constituting the detecting coil and a superconductive film at a vicinity of the detecting coil are larger than an inner diameter of the detecting coil, there is constructed a superconductive quantum interference element having a structure provided with a slit at a detecting coil and/or a superconductive film at a periphery of the detecting coil.

Abstract: The invention concerns a method, a system and a device for producing, from a substance, electric signals characteristic of the biological activity of an active element contained in the substance. The method consists in: placing the substance in a zone subjected to a specific electric, magnetic and/or electromagnetic excitation field. The method further includes a step which consists in transforming the fields resulting form the interaction between the specific excitation filed and the substance, into signals, in particular electric signals, using a first transducer receiving the resulting fields.

Abstract: A magnetic field measuring apparatus has a magnetic field shielding apparatus including non-magnetic cylindrical members on which high-permeability sheets are located in a state of being partially overlapped with each other. The cylindrical members are located to surround an axis of a first direction concentrically and having a hollow portion, the cylindrical member located on an innermost-side having a first opening at one end of the first direction, a second opening at the other end of the first direction, and a third opening penetrating the cylindrical members in a direction perpendicular to the axis of the first direction. In addition, the magnetic field measuring apparatus has a living-body holder located in an inner-side space of the cylindrical member and a cryostat inserted into the third opening and maintaining SQUID magnetic-flux meters.

Abstract: A device for carrying out measurements of a quantity through measuring the influence upon a magnetic field generated through a basic signal in a region of measurement (16) has a first member (7) adapted to change the polarity of the basic signal in a regular way on the basis of the length of the time for regularly repeating the basic signal, or a multiple thereof, and a second member (9) adapted to change the polarity of a detection signal in connection with the treatment of this detection signal synchronizedly with the polarity change of the first member.

Abstract: A system and method for realizing vector Kerr magnetometry are disclosed. The system enables simultaneous longitudinal and transverse Kerr effect measurements at each point on a sample surface. An optional component includes a sample platform for achieving precise linear and rotational relocation. The repositionable platform enables complete, 360 degree characterization about a single point. Additionally, the platform control mechanism may be utilized in obtaining longitudinal and transverse Kerr effect measurements at succeeding points on the surface of a sample. Rapid sample characterization is thus achieved.

Abstract: An inductive linear position sensor, particularly for use with motor vehicles has an oscillator circuit for creating a periodic alternating voltage signal, an exciting coil coupled to the oscillator circuit, a plurality of receiving coils with the exciting and receiving coils being structured as leads on a circuit board, evaluation circuitry for evaluating signals induced in the receiving coils and a movable inductive coupling element for influencing the strength of inductive coupling between the exciting coil and the receiving coils. The evaluation circuitry is arranged within the geometry of at least one of the sending (exciting) and receiving coils. Effective surface areas of the receiving coils are structured at beginning and end areas of the sensor such that, when there is no movable element present, a zero voltage results at the output taps of the receiving coils.

Abstract: An eddy current inspection probe for inspecting a preselected surface at least partially defining an opening in a component. The probe includes a cast core having an exterior surface sized and shaped for receipt within the opening of the component and an eddy current array positioned over the exterior surface of the core for generating and detecting magnetic fields in the component to inspect the preselected surface of the component.

Abstract: An apparatus for measuring induced polarization of the ground. The apparatus includes a polarizable contact member configured to transmit a current to the ground. An electrode includes a first conductor and a second conductor. The first conductor is coupled to the polarizable contact member. A non-polarizable contact member is coupled to the second conductor of the electrode and is configured to measure an electrical potential associated with the current.

Abstract: Through differentiation of input signal Vw from a sensor the angular frequency &ohgr; becomes included in the amplitude component. Through a plurality of differential operations the amplitude including the angular frequency &ohgr; varies, but the time-dependent term becomes equal. Since the amplitude of the signal Vw outputted from the revolution speed sensor 10 is approximately constant, the angular frequency &ohgr; proportional to the revolution speed can be extracted by determining a ratio thereof.

Abstract: A position detecting apparatus including a magnetic scale and a magnetic sensor for detecting a magnetic field generated by the magnetic sensor. The magnetic field extending in a magnetism-sensing direction perpendicular to a first direction in which the magnetic sensor moves relative to the magnetic scale and a second direction in which the magnetic sensor is spaced from the magnetic scale. The positional relationship between the magnetic scale and the magnetic sensor is detected from the magnetic field detected by the magnetic sensor in the magnetism-sensing direction.

Abstract: The probe for inspecting electrically conducting parts (1) of the invention comprises a row of transmitter and receiver coils (27), (28) that form an array of energized coils. The receiver coils (28) are influenced by different magnetic fields created by several neighboring transmitter coils (27) at the same time, making them sensitive to different types of flaws. The array of energized coils is displaced along the row. The probes are usually used for inspecting steam generator tubes of nuclear power plants.

Abstract: A method for adjusting a sensor so that its output signal will indicate a tooth edge location coinciding with the nominal center line of the sensor, or coinciding with any other specified point on the face of the sensor. The proposed method applies to all types of sensors (magnetic and otherwise) which rely on the comparison between input and reference signals to generate a binary output signal. As a part of the manufacturing process, each sensor is oriented and located with respect to a stationary segment of a target wheel identical to that which will be subsequently used in operation. It is preferred for the segment to include a portion of a tooth, a portion of a slot, and one tooth edge specified as either falling or rising. The tooth edge is precisely aligned with the centerline of the sensor at a desired offset angle with respect to the actual tooth edge measured from the center of the target wheel. Now the reference level is adjusted until the output signal switches state.

Abstract: In accordance with the present invention, a non-contacting position sensor using bipolar tapered magnets is provided. A non-contacting position sensor in accordance with the preferred embodiment uses a pole piece having a first plate and a second plate. Four magnets are affixed to the first plate and second plate. Each magnet has a thick end and a thin end. Two magnets generate a linearly varying magnetic field having a first polarity, while the other two magnets generate a linearly varying magnetic filed having a second polarity. An air gap is formed in the space between the four magnets. A magnetic flux sensor is positioned within the air gap. The component whose position is to be monitored is rigidly attached to either the pole piece or the magnetic flux sensor, causing the magnetic flux sensor to move relative to the magnets within the air gap as the component moves.