Abstract: An eddy current flaw detection device according to an embodiment includes: a first exciter/detector that is supplied with alternating current and can induce eddy current in a tested object by generating a magnetic field change in the tested object; a second exciter/detector disposed opposite side of the first exciter/detector sandwiching the tested object therebetween. The second exciter/detector can detect a change in a reactive magnetic field generated by the eddy current. The first and second exciter/detectors each may have a coil including a helical coil wire, and the coil wire of the first exciter/detector may be thicker than the coil wire of the second exciter/detector.

Abstract: Determining a Curie temperature (Tc) distribution of a sample comprising magnetic material involves subjecting the sample to an electromagnetic field, heating the sample over a range of temperatures, generating a signal representative of a parameter of the sample that changes as a function of changing sample temperature while the sample is subjected to the electromagnetic field, and determining the Tc distribution of the sample using the generated signal and a multiplicity of predetermined parameters of the sample.

Abstract: A sensor element based on a magneto-thermoelectric effect and realizing method thereof are provided, the sensor element includes a plurality of thermoelectric elements having an angular structure and are located in a magnetic field; the thermoelectric element is made of magnetic material having a thermoelectric effect, and includes a first side, a second side, and an angular part formed by connecting the two sides; the angular part is provided with a heating device; and the temperature in the region where the other end of the first side and the second side are located are less than or equal to the ambient temperature.

Abstract: A thermomagnetic temperature sensor, a temperature measurement system and a method of measuring temperature employ a temperature-dependent resonant frequency of a thermomagnetic resonator to measure temperature. The thermomagnetic temperature sensor includes a thermomagnetic inductor and a capacitor connector to form the thermomagnetic resonator. The thermomagnetic inductor includes a ferromagnetic material having a temperature-dependent magnetic permeability to determine the temperature-dependent resonant frequency. A predetermined relationship between the temperature-dependent resonant frequency and temperature in a range between a maximum magnetic permeability value and a Curie temperature provides the measurement of temperature.

Abstract: The present invention relates to an apparatus and a method for void size determination of voids within an object into which an aerosol containing magnetic particles has been introduced, in particular for determining the size of a patient's pulmonary alveoli, said patient having inhaled an aerosol containing magnetic particles To review information concerning the lung structure, it is proposed to use magnetic particle imaging. First and second detection signals are acquired subsequently at different moments in time after introduction of the aerosol containing the magnetic particles into the object, in particular after inhalation of the aerosol by the patient. These detection signals are exploited, in particular the drop in intensity and/or the signal decay time, to get information about the diffusion of the magnetic particles within the voids, in particular alveoli, and to retrieve information therefrom about the size of the voids, in particular alveoli.

Abstract: A gasket according to the present invention is for sealing a valve or pipe used in a high-pressure gas supplying equipment, which is comprised of a polymer material containing magnetic particles. Also, in a determination method of deterioration and damages of a gasket according to the present invention, the aforementioned gasket is used as the gasket for sealing a valve or pipe in a high-pressure gas supplying equipment, and the magnetic force of the gasket is measured to determine the deterioration and the damages of the gasket.

Abstract: The invention provides a method for accurately calibrating a vacuum thermogravimetric analyzer (VTGA). The invention solves the problem of calibrating a VTGA by using the actual magnetic transitions and associated transition temperatures, or Curie temperatures, Tc's, of a set of standards which can be used in-situ at the location of the sample holder obviating the difficulties associated with indirect methods of calibration. The invention encompasses a method of using a set of calibration standards comprised of a plurality of ferromagnetic slugs to provide a temperature calibration for a VTGA. The method permits accurate calibration through sufficiently numerous calibration points over a rather limited low-temperature range for determining vapor pressures of compounds. Through the use of these standards, highly accurate measurements can be made of the vapor pressures of critical hard disk drive compounds, such as lubricants, and corrosion inhibitors, that are crucial to competitive disk drive technology.

Abstract: A method and system for providing real-time, closed-loop control of the induction hardening process. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

Abstract: A method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

Abstract: Techniques for ultrahigh density writing on an erasable magnetic medium include using a micromachined mechanism having two probes for writing to the medium. Use of the two probe embodiment eliminates the need to change the magnetic orientation of the probe. In another embodiment, a single probe is provided which is heated to the vicinity of its Curie temperature to enable the magnetic orientation of the probe to be switched. The probe may be heated to its Curie temperature through the use of a heating element or a focused laser. In another embodiment of the present invention, either the magnetic orientation of the probe or the magnetic orientation of the medium may be switched through the combination of a static magnetic field, a radio frequency magnetic field and, under certain circumstances, the magnetic field of the probe. In all cases, the writing techniques enable information to be written to a magnetic medium in a manner which enables the information to be erased and the medium rewritten.

Abstract: A method of and apparatus for measuring the degree of transformation of the structure of an object. An object is placed between a transmission coil and a receiving coil. An A.C. current or a pulse current or a combination of the A.C. current and the pulse current are supplied to the transmission coil, and the degree of transformation is detected by means of an electric signal obtained through the receiving coil.

Abstract: A detector is disclosed including a temperature sensitive amorphous magnetic alloy which shows a Curie point of not higher than 200.degree. C. and whose composition is represented by the formula:(M.sub.1-a Ni.sub.a).sub.100-z X.sub.zwherein M=Co or Fe; X=at least one of P, B, C and Si; 0.2.ltoreq.a.ltoreq.0.8 when M is Co, or 0.4.ltoreq.a.ltoreq.0.9 when M is Fe; and 15.ltoreq.z.ltoreq.30.

Abstract: There is disclosed a method and arrangement for inspecting the surface of steel stock having a temperature above the Curie point. In order to detect, with a great certainty and accuracy, defects in the hot steel stock, with a loss of energy for cooling the steel stock for inspection and subsequently reheating it for further processing being avoided, only a thin surface layer of the steel stock is intensively cooled on the surface to be inspected, to a temperature below the Curie point. The core of the steel remains hot. Immediately thereafter, a magnetic or electromagnetic field is induced in the cooled surface layer and disturbances in the induced field caused by defects in the steel stock are detected and recorded by pick-ups.

Abstract: A device for detecting phase transformations in a magnet material is disclosed. A sample is placed in a coil coupled to a harmonic oscillator and subjected to heat radiation means for simulating predetermined heating and cooling rates which result in phase transformations within the material being tested. The phase transformations are a function of changes in magnetic permeability which vary with temperature changes.

Abstract: A temperature-responsive circuit comprising an ECTS reed switch and an interrogation means for determining the operability and accuracy of the temperature-responsive portion of the circuit.