The invention relates to a method for observing a magnetic field of a material volume, in particular for determining properties of a workpiece under, in particular, magnetic, mechanical, thermal, and/or electrical excitation of a material volume of the workpiece, wherein the magnetic field of the material volume is sensed as a function of time and of frequency with high frequency resolution.

Provided are: a mechanical property measuring apparatus and method that can accurately measure a mechanical property through physical quantities; a substance manufacturing equipment and method that can improve the production yield rate. A mechanical property measuring apparatus (100) comprises: a physical quantity measuring unit (5) configured to measure a plurality of physical quantities of a measured object that includes a substance and a film on a surface of the substance; a classification processing unit (81) configured to select one of a plurality of calculation models (M.sub.1, M.sub.2, . . . , M.sub.n) for calculating a mechanical property of the substance, based on at least two of the plurality of physical quantities measured; and a mechanical property calculating unit (82) configured to calculate the mechanical property of the substance using the calculation model selected by the classification processing unit (81) and the at least two of the plurality of physical quantities.

Provided are: a mechanical property measuring apparatus and method that can accurately measure a mechanical property through physical quantities; a substance manufacturing equipment and method that can improve the production yield rate. A mechanical property measuring apparatus (100) comprises: a physical quantity measuring unit (5) configured to measure a plurality of physical quantities of a measured object that includes a substance and a film on a surface of the substance; a classification processing unit (81) configured to select one of a plurality of calculation models (M.sub.1, M.sub.2, . . . , M.sub.n) for calculating a mechanical property of the substance, based on at least two of the plurality of physical quantities measured; and a mechanical property calculating unit (82) configured to calculate the mechanical property of the substance using the calculation model selected by the classification processing unit (81) and the at least two of the plurality of physical quantities.

A surface property evaluation method includes a measurement step for acquiring the distribution of impedance in the depth direction of a test piece, and an evaluation step for evaluating the surface treatment state in the depth direction and wherein the evaluation step includes: a step for creating a reference measurement value group by preparing untreated sample, good sample, and sample to be evaluated, and calculating an impedance ratio γ1 at each frequency for the untreated sample and good sample impedances; a step for creating an evaluation measurement value group by calculating an impedance ratio γ2 for the impedances of untreated sample at each frequency relative to the sample to be evaluated impedances; and a step for evaluating the surface treatment state of a sample to be evaluated by comparing a reference measurement value group with the evaluation measurement value group.

A damage evaluation apparatus, to evaluate damage to a tendon embedded in concrete. The apparatus includes a magnetizer for generating magnetic force, and a detector for detecting change in magnetism produced from a damaged area of the tendon when magnetized. The magnetizer includes a excitation coil; an iron core passing through a center hole of the excitation coil; a pair of columnar yokes connected to respective ends of the iron core and extending toward the concrete; and a pair of plate-shaped yokes connected to the pair of columnar yokes at a distal end thereof for forming magnetic poles having spread along the surface of the concrete. By passing an electric current through the excitation coil, a magnetic circuit is formed by the yoke shaft, the pair of columnar yokes, the pair of plate-shaped yokes, and the tendon over a range thereof situated between the pair of plate-shaped yokes.

A damage evaluation apparatus, to evaluate damage to a tendon embedded in concrete. The apparatus includes a magnetizer for generating magnetic force, and a detector for detecting change in magnetism produced from a damaged area of the tendon when magnetized. The magnetizer includes a excitation coil; an iron core passing through a center hole of the excitation coil; a pair of columnar yokes connected to respective ends of the iron core and extending toward the concrete; and a pair of plate-shaped yokes connected to the pair of columnar yokes at a distal end thereof for forming magnetic poles having spread along the surface of the concrete. By passing an electric current through the excitation coil, a magnetic circuit is formed by the yoke shaft, the pair of columnar yokes, the pair of plate-shaped yokes, and the tendon over a range thereof situated between the pair of plate-shaped yokes.

A damage evaluation apparatus, which is used on a concrete structure having an embedded tendon to be evaluated for damage. The damage apparatus includes a magnetizer for generating magnetic force, and a detector for detecting a change in magnetism produced from a damaged area of the tendon. The magnetizer includes an excitation coil; an iron core passed through a center hole of the excitation coil; and a pair of columnar yokes connected to respective ends of the iron core and each extending toward the surface of the concrete. By passing an electric current through the excitation coil, a magnetic circuit is formed by the yoke shaft, the pair of columnar yokes, and the tendon over a range thereof situated between a pair of plate-shaped yokes. Current that flows through the excitation coil is controlled such that the magnetic flux density of the tendon is rendered constant.

A damage evaluation apparatus, which is used on a concrete structure having an embedded tendon to be evaluated for damage. The damage apparatus includes a magnetizer for generating magnetic force, and a detector for detecting a change in magnetism produced from a damaged area of the tendon. The magnetizer includes an excitation coil; an iron core passed through a center hole of the excitation coil; and a pair of columnar yokes connected to respective ends of the iron core and each extending toward the surface of the concrete. By passing an electric current through the excitation coil, a magnetic circuit is formed by the yoke shaft, the pair of columnar yokes, and the tendon over a range thereof situated between a pair of plate-shaped yokes. Current that flows through the excitation coil is controlled such that the magnetic flux density of the tendon is rendered constant.

Pulsed Field Magnetometry (PFM) method and apparatus to compensate for zero signal errors in a material characterisation process involving first constructing a synthesised zero signal expressed with a range of variable parameters. A measurement cycle is performed on a sample of material to be characterised the waveform data obtained in said measurement cycle is stored. The synthesised zero signal is then applied to the stored data while adjusting the values of the variable parameters, and the values are selected which best fit the synthesised zero signal to the stored data. The synthesised zero signal with the selected values is then removed from the stored data to obtain compensated material characterisation data.

The invention relates to a method for observing a magnetic field of a material volume, in particular for determining properties of a workpiece under, in particular, magnetic, mechanical, thermal, and/or electrical excitation of a material volume of the workpiece, wherein the magnetic field of the material volume is sensed as a function of time and of frequency with high frequency resolution.