An induction pressing plate type real-time monitoring apparatus, including a fixing portion, an abutting portion, and an inductor. The fixing portion has a hole for fixing and connecting a fastener to an upper or lower platform of a forming device. The abutting portion is connected to the fixing portion, and the abutting portion in at least part of a pressure surface region is configured to press a tested piece to be induced. The inductor is disposed at the abutting portion, and has an induction unit for inducing actual information transmitted to the abutting portion by the direct contact of the tested piece and converting the actual information into measurable data, an output unit for outputting the data, and a power supply unit for providing power to the induction unit and the output unit.

A variety of applications can include apparatus and/or methods that provide an axial force transducer. Two coils wound coaxially with respect to each other can be used with a magnet to determine a distance traveled based on application of an axial force to an instrument component. The two coils and magnet can be configured in a number of ways with respect to the instrument component. In various embodiments, the difference between an inductance associated with one of the two coils along with its relation to the magnet and an inductance associated with the other one of the two coils along with its relation to the magnet can be used to determine the axial force on the component of the instrument associated with the distance travelled. Additional apparatus, systems, and methods are disclosed.

A force sensor has a sensing system including a target piece and a sensing element, configured to provide changes of a magnetic field, being generated by motion of the target piece. The sensing element senses these changes and provides a signal representative of the position of the target piece. An integrated circuit with processing means can process signals from the sensing element. A semiconductor package includes at least the integrated circuit. A flexible piece includes the target, and it is attached to the semiconductor package. The attachment area between the flexible piece and the semiconductor package does not extend beyond the top projection, or outline, of the semiconductor package. The flexible piece receives a force stimulus, so that upon exerting a force on the flexible piece, the displacement of the target piece with respect to the surface of the semiconductor package can be sensed by the sensing element.

A method for stress-induced magnetic field signal acquisition and stress measurement is disclosed. The method can include the following steps: a1, conducting AC magnetization on a to-be-tested structure by using an AC magnetic field with preset frequencies and strengths, and acquiring the excitation magnetic field signals in at least one cycle; a2, subtracting the excitation magnetic field signals in at least one cycle of a stress-free sample having the same material as the to-be-tested structure from the excitation magnetic field signals acquired in step a1 to obtain a stress-induced magnetic field signals of the to-be-tested structure; a3, quantitatively assessing the stresses in the to-be-tested structure by comparing the mean values of the stress-induced magnetic field signals acquired in step a2 with the pre-calibrated relationship of stresses and the mean values of the stress-induced magnetic field signals for the material of the to-be-tested structure.

A stress distribution measurement device includes: a first magnetostrictive sensor and a second magnetostrictive sensor each including an excitation coil that excites AC magnetism in a measurement target using alternating current, and a detection coil to which alternating current is induced due to the AC magnetism flowing in the measurement target; an excitation circuit that applies a first excitation voltage to the excitation coil of the first magnetostrictive sensor and applies a second excitation voltage to the excitation coil of the second magnetostrictive sensor, the second excitation voltage having a phase or a waveform different from the first excitation voltage; and a detection circuit that includes a first detector that performs synchronous detection of current flowing in the detection coil of the first magnetostrictive sensor based on the first excitation voltage and a second detector that performs synchronous detection of current flowing in the detection coil of the second magnetostrictive sensor based on the second excitation voltage.

To improve the output signal quality of a load measurement by means of active magnetization, the invention provides a load measurement method for measuring a mechanical load on a test object (14), comprising: a) generating and applying a magnetic field to the test object (14); b) detecting a magnetic field changed by the test object (14) as a result of a mechanical load on the test object (14) by means of a first magnetic field detection device (20) to generate a first measurement signal (U1, UAB), c) detecting a magnetic field changed by the test object (14) as a result of a mechanical load on the test object (14) by means of a second magnetic field detection device (22) to generate a second measurement signal (U1, UAB), d) computationally determining a third measurement signal (UBT) from the first measurement signal (U1, UAB) and the second measurement signal (U2, UAT), and preferably comprising the steps of e) forming a difference from one (U2, UAT) of the first and the second measurement signals and the computationally determined third measurement signal (UBT) to produce an output signal, f) determining the mechanical load applied to the test object (14) based on the output signal. The invention also provides a corresponding load measurement device for carrying out the load measurement method.

A sensor for sensing stress in a ferromagnetic material includes a non-magnetic substrate. The substrate has a first surface and a second surface opposite the first surface. A first coil is attached to or formed on the first surface of the substrate. The first coil is configured to induce a magnetic flux in the ferromagnetic material being driven by an alternating current (AC) signal. At least one second coil is attached to or formed on the first surface of the substrate. The at least one second coil is spaced from the first coil. In addition, the second coil is configured to detect changes in the magnetic flux induced in the ferromagnetic material.

A tactile sensor has an elastically deformable sheet, a coil that is provided in the sheet, a powdery or fibrous magnetic material that is provided in the sheet with the coil, and a detection portion that detects an inductance of the coil. The coil is wound in a spiral shape and the powdery or fibrous magnetic material is dispersed in the sheet.

Techniques for force sensing in additive fabrication are provided. According to some aspects, an additive fabrication device may include a force sensor configured to measure a force applied to a build platform during fabrication. A length of time taken for a layer of material to separate from a surface other than the build platform to which it is adhered may be determined based on measurements from the force sensor. Subsequent additive fabrication operations, such as subsequent motion of the build platform, may be adapted based on the determined length of time.

A sensor arrangement for measuring a mechanical loading, comprising a first member to be mechanically loaded; a first sensor component arranged on the first member; a printed circuit board (PCB); a second sensor component arranged on the PCB and spaced from the first sensor component, wherein an output signal of the second sensor component is indicative of the distance between the first and second sensor components; and an electronic component arranged on the PCB and configured to receive the output signal of the second sensor component, wherein the sensor arrangement is configured such that the distance between the first and second sensor components depends on the mechanical loading applied to the first member.