Non-contact coaxial magnetoelastic sensor

Abstract

The invention discloses a non-contact coaxial magnetoelastic sensor, belonging to the technique field of measurement. The non-contact coaxial magnetoelastic sensor comprises a first PVC tube (polyvinylchloride tube), a second PVC tube, a third PVC tube, a biasing coil, an excitation coil, a receiving coil and a soft magnetic belt material, wherein the first PVC tube is coaxially sleeved outside the second PVC tube, the second PVC tube is coaxially sleeved outside the third PVC tube, top ends of the first PVC tube, the second PVC tube and the third PVC tube are aligned to each other, a single layer of the biasing coil is enwound on the outer surface of the first PVC tube, a single layer of the excitation coil is enwound on the outer surface of the second PVC tube, a single layer of the receiving coil is enwound on the outer surface of the third PVC tube, and the soft magnetic belt material is arranged inside the third PVC tube. The receiving coil comprises a first sub-coil and a secondsub-coil, and the first sub-coil is oppositely connected in series with the second sub-coil. The invention has the advantages of compact structure, small volume, high flexibility and high accuracy ofreceiving signals.

Description

technical field [0001] The invention relates to a sensor in the field of measurement technology, in particular to a non-contact coaxial magnetoelastic sensor. Background technique [0002] When the soft magnetic metallic glass strip is excited by the AC magnetic field pulse, due to the magnetoelastic coupling effect, it will generate forced mechanical vibration in the strip, and at the same time emit a changing magnetic flux in the surrounding space of the strip. Its vibration condition is monitored. When the excitation of the AC pulse magnetic field stops, the amplitude of the strip will gradually decay. In order to increase the magnetoelastic coupling performance of the sensor to enhance the vibration amplitude, it is usually necessary to superimpose a DC bias magnetic field to offset the magnetic anisotropy of the strip. Compared with piezoelectric sensors such as quartz crystal microbalance (QCM) or surface acoustic wave sensor (SAW), the strip magnetic field excitation...

AI Technical Summary

Problems solved by technology

Although the sensor can effectively eliminate the induction signal generated by the exciting coil in the receiving coil and realize the real-time detection of strip vibration signals, its two receiving sub-coils are non-coaxial, with a large area, an uncompact structure, and a large coil width. Smaller than the length, and the multi-layer coil winding method is easy to form additional parasitic capacitance between layers, which affects the received signal waveform. In addition, the strip is placed outside the coil, and the reception of the magnetic flux of the strip is limited, which affects the received signal amplitude.

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