# US 10,871,469 B2 · Surface sensing method for corrosion sensing via magnetic modulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,469 B2 - Document ID: US10871469B2 - Status: Granted - Kind: B2 - Application number: 16/032,553 - Filed: 2018-07-11 - Published: 2018-11-08 - Granted: 2020-12-22 - Earliest claimed: 2014-04-16 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Leonardo William Estevez; Terry Lee Sculley; Christian Link - Web page: https://patentgrep.com/patent/US10871469B2 ## CPC - G01N 27/82: for investigating the presence of flaws - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A method includes pulsating a magnetic field at a first location associated with an external surface of a wall containing magnetic material. The method also includes measuring at least one characteristic of the pulsating magnetic field at a second location associated with the external surface of the wall. The at least one characteristic changes based on corrosion on an internal surface the wall between the first and second locations. The magnetic field could be pulsated by applying an AC signal to a conductive coil or by vibrating a magnet. The method could also include analyzing the at least one measured characteristic to identify an amount of the corrosion and/or a change in the amount of the corrosion. Use of the internal surface the wall could be modified based on the amount or change of the corrosion. Multiple magnetic fields can be generated at multiple first locations, and the at least one characteristic can be measured at multiple second locations. ## Claims ### Claim 1 An apparatus comprising: a magnet; an electromechanical transducer coupled to the magnet; and a support supporting the magnet and the electromechanical transducer; and the electromechanical transducer configured to vibrate the magnet by rotating the magnet or by horizontally vibrating the magnet. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the support is a coil. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the support is a flexible platform. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the support comprises an energy harvester for harvesting kinetic energy from the support, to generate electrical energy. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the magnet generates a magnetic field in the form of a magnetic flux. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the electromechanical transducer is configured to: receive an electrical signal; and pulse the magnet at a frequency corresponding to the electrical signal. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein pulsing the magnet comprises performing amplitude modulation on a magnetic field generated by the magnet. ### Claim 8 (depends on 6) The apparatus of claim 6, wherein pulsing the magnet comprises performing frequency modulation on a magnetic field generated by the magnet. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the electromechanical transducer is a piezoelectric diaphragm. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the magnet is configured to pulsate at a frequency of natural vibration of the support. ### Claim 11 A system comprising: a pulsating magnetic field generator configured to generate a pulsating magnetic field, the pulsating magnetic field generator comprising: a magnet; a support; and an electromechanical transducer coupled to the support the, electromechanical transducer coupled to the magnet, and the electromechanical transducer configured to vibrate the magnet and the support; and a sensor configured to measure at least one characteristic of the pulsating magnetic field, to generate at least one measurement characteristic of the pulsating magnetic field. ### Claim 12 (depends on 11) The system of claim 11, wherein the system comprises an array comprising multiple pulsating magnetic field generators and multiple sensors. ### Claim 13 (depends on 11) The system of claim 11, the sensor comprising a magnetometer, the magnetometer comprising a transducer, the transducer of the magnetometer configured to generate an electrical signal in response to detecting a magnetic flux. ### Claim 14 A method comprising: supporting, by a support, a magnet and an electromechanical transducer; and vibrating, by the electromechanical transducer, using the support, the magnet, to generate a pulsating magnetic field, by amplitude modulating or frequency modulating the pulsating magnetic field. ### Claim 15 (depends on 14) The method of claim 14, wherein vibrating the magnet comprises vibrating the magnet by a rotation of the magnet at a specified angular velocity, vibrating the magnet by a horizontal vibration, or vibrating the magnet by a vertical vibration. ### Claim 16 (depends on 14) The method of claim 14, further comprising: receiving, by the electromechanical transducer, an electrical signal; and pulsing, by the electromechanical transducer, the magnet at a frequency corresponding to the electrical signal. ### Claim 17 (depends on 14) The method of claim 14, further comprising harvesting, by the support, kinetic energy from the support, to generate electrical energy. ### Claim 18 (depends on 14) The method of claim 14, wherein the magnet pulsates at a natural frequency at a frequency of natural vibration of the support. ### Claim 19 (depends on 14) The method of claim 14, wherein vibrating the magnet comprises vibrating the magnet by a rotation of the magnet at a specified angular velocity or vibrating the magnet by a horizontal vibration. ### Claim 20 A device comprising: a magnet; a piezoelectric diaphragm coupled to the magnet; and a support supporting the magnet and the piezoelectric diaphragm; and the piezoelectric diaphragm configured to vibrate the magnet and the support.