Abstract: The magnetic powder for validity determining ink is composed of magnetic oxide power having a Curie temperature between −50°C. and 150°C. and a mean powder particle diameter of 10 &mgr;m or less.

Abstract: In at least one measuring rod of the length measurement system the direction of magnetization lies in the plane of its cross-section which is perpendicular to the direction of measurement and forms a magnetization pattern. In the simplest case the magnetization of the cross-section is homogeneous. As one advances in the direction of measurement the magnetization pattern is increasingly rotated in relation to the starting end of the measuring rod. This magnetization results in a magnetic field whose direction is also continuously rotated as one advances in the direction of measurement. By means of at least one magnetic field sensor which responds to the direction of the magnetic field the prevailing field angle for each position is determined and can be clearly assigned to the position for a multitude of different variants of the length measurement system.

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 position transducer includes a bias circuit that drives and controls first and second bias coils. The bias circuit monitors the value of a voltage produced in a second sensor coil and drives and controls the first and second bias coils such that the value of the voltage produced in the second sensor coil is always equal to a desired voltage value.

Abstract: Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

Abstract: A high torque electromagnetic device such as a moving magnet galvanometer includes a composite electromagnetic coil. The composite electromagnetic coil includes two pancake-shaped coil parts made using a rectangular conductor having a width and a thickness, wherein the winding formed for each pancake-shaped coil part has the width oriented in a direction substantially normal to the initially flat face of the pancake-shaped coil part. Each pancake-shaped coil part is subsequently shaped to a shape different from the initially flat shape. The coil parts are superposed and electrically connected to form a single tightly packed unit.

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 and a method to detect a broken tooth in a pulse signal by measuring one pulse cycle and another pulse cycle, determining whether a ratio of one pulse cycle and another pulse cycle is a multiplied number while wheel speed is constant.

Abstract: An apparatus and method for locating subsurface objects using an induction array system is presented. The system uses a movable array that contains two or more spatially separated receivers and one or more spatially separated transmitters. The spatial separation permits the array to detect objects at varying depths with a single pass of the device over the surface area under investigation. If multiple transmitters are used, then they may either be operated simultaneously at different frequencies or sequentially at the same frequency. The spacing between receiver and transmitter elements in the induction array may be uniform or non-uniform.

Abstract: Two lines of magnets have the same length and are aligned side by side. The lines of magnets have different numbers of magnetic pole pairs and have equal line lengths. A first sensor determines a relative position between poles of a pole pair of the first line of magnets, and a second sensor determines a relative position between poles of a pole pair of the second line of magnets. A circuit compares the relative positions determined by the sensors to determine an absolute position of the first line of magnets.

Abstract: A pedal and sensor assembly for mounting to a vehicle. The assembly has a pedal arm having a first end and a second end. A magnetic field generator is connected to the second end to generate a variable magnetic field as the pedal moves. A housing is attached to the vehicle and has the second end and the magnetic field generator contained therein. A magnetic field sensor is located adjacent to the magnetic field generator and detects the variable magnetic field such that as the pedal arm rotates the magnetic field sensor generates an electrical signal proportional to the strength of the variable magnetic field and that is indicative of the position of the pedal arm.

Abstract: A transmission selector position sensor is designed for easy integration into a transmission assembly. The transmission selector position sensor includes a Hall effect sensor carried on a stationary member to be mounted to the transmission body and a magnetic field generator to be mounted to a rotatable member mounted to the selector shaft. The sensor assembly is made so that the stationary member carries the rotating member prior to installation in the transmission, and then is not a load bearing member after installation.

Abstract: Within a body, a sensor member, which has one end supported in a cantilever fashion adjacent a predetermined end of the body and has the other end extending into a space of the body, includes a coil section having a plurality of coil segments that are excitable in a same phase by a predetermined A.C. signal and sequentially arranged along a direction of linear movement of a movable member. The movable member has an inner space to permit entry of the sensor member into the movable member. Inner peripheral wall of the movable member defining the inner space includes a magnetism-responsive substance containing a magnetic or electrically-conductive material.

Abstract: An apparatus for detecting the angular position of a first rotatable body (10, L) has a number n of uniform angle markings or teeth (11), with at least two rotatable gear wheels (12, 13, 14, 15), which respectively have n1, n2, n3, n4 uniform angle markings or teeth. The angle markings of the at least two rotatable gear wheels (12, 13, 14, 15) cooperate with the angle markings (11) of the first rotatable body (10) in such a way that by detecting the angular positions &thgr;, &psgr; of the at least two rotatable gear wheels (12, 13, 14, 15), the angular position a of the first rotatable body can be determined. When there are two of the at least two rotatable gear wheels (12, 13; 12, 14; 12, 15; 13, 14; 13, 15; 14, 15), ¦ni-nj¦>1 and (ni, nj)=1 or ni, nj are relatively prime and when there are more than two of the at least two rotatable gear wheels, (ni, nj)=1, where 1=i<N, with N being the total number of the at least two rotatable gear wheels (12, 13, 14, 15).

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: In an evaluation circuit for evaluating an output signal of a magnetoresistive sensor (1) for rotational speed measurement, in which the evaluation circuit performs an offset compensation of the sensor signal and comprises a comparator (4) which receives the offset compensated sensor signal and compares it with a reference voltage, a reliable identification of the output signal of the sensor after switching on the arrangement is ensured in that, in an initial mode, the value of the reference voltage is selected in dependence upon the temperature, the temperature dependence being approximated to that of the sensor signal, in that a control unit (6) is provided which, in the initial mode, consecutively checks whether the sensor signal is present, triggers the offset compensation only after the presence of said signal, subsequently checks whether the comparator (4) supplies an output signal, and changes over to a control mode only after the presence of said signal, in which control mode the temperature dependenc

Abstract: An angular position detection device has a rotor that comprises two magnets and a primary yoke, and a stator that comprises a pair of auxiliary yokes and a magnetism detection element. The rotor is fixed to a rotary shaft of an object to be detected. The primary yoke forms a magnetic circuit in a ring, and the magnets are configured so that the intensity distribution of the magnetic field is asymmetric with respect to the center of rotation of the rotor. The magnetism detection element is placed in a gap between the auxiliary yokes. This stator is disposed in the inside of the rotor so that an air gap between the rotor and the stator varies gradually in the circumferential direction. Thus, the magnetism detection element is enabled to produce a linear output over a range wider than 180°.

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: The invention concerns a testing procedure for detecting nonuniformities in the wall thickness of inaccessible metallic pipes in which electrical alternating currents of different frequencies are passed through the pipe and the magnetic fields generated by them are measured outside the pipe. The invention further concerns a device, particularly for carrying out the testing procedure, comprising a power source for passing an alternating current through the pipe, at least one magnetic field probe for measuring outside the pipe the magnetic field generated by the alternating current, and equipment for the evaluation which deduces the presence of a nonuniformity in wall thickness from the magnetic field signal of the magnetic field probe.

Abstract: A single die MR sensor having three MR elements each being preferably composed of a number of serially connected MR segments for use in linear position sensing schemes. The MR sensor is, generally, aligned in the direction of movement of a magnetic target. The middle MR element is the actual position sensor. The two outer MR elements serve as reference sensors which sense the magnetic field at the limits of the position sensing range. The cooperating magnetic target assures that one of the two outer MR elements is always exposed to some maximum magnetic field, BMAX, corresponding to a position XMAX, and the other MR element is always exposed to some minimum magnetic field, BMIN, corresponding to a position XMIN, and wherein a portion of the middle MR element is exposed to BMAX and another portion of the middle MR element is exposed to BMIN, wherein the position, X, of the target is computed assuming uniformity of the middle MR element along its length.