Measurement method and measurement arrangement for interference suppression in a receive signal of an EMAT transducer

Patent metadata

Field	Value
Publication number	US-12209995-B2
Application number	US-202117466256-A
Country	US
Kind code	B2
Filing date	Sep 3, 2021
Priority date	Sep 3, 2020
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

A measurement method is provided on an electrically conducting object. A first ultrasound wave is generated in the object by means of a first EMAT transmit transducer of a measurement arrangement. A first EMAT receive transducer of the measurement arrangement detects a first receive signal. The first receive signal comprises a first ultrasound signal resulting at least partially from the first ultrasound wave which has propagated through at least a part of the object, as well as a first electromagnetic interference signal. A second receive signal is also detected comprising a second electromagnetic interference signal by means of a first receive means of the measurement arrangement. The first receive signal and the second receive signal are processed jointly. At least the first receive signal is at least partially interference-suppressed.

First claim

The invention claimed is:

1. A measurement method on an electrically conducting object, the measurement method comprising the steps of:
generating a first ultrasound wave in the object by a first EMAT transmit transducer of a measurement arrangement which is positioned on or near a surface of the object and which has a first transmit transducer induction coil having at least one conductor path, and
receiving a first receive signal, by a first EMAT receive transducer which is positioned on or near the surface of the object and which has a first receive transducer induction coil having at least one conductor path, wherein the first receive signal comprises a first ultrasound signal resulting at least partially from the first ultrasound wave which has propagated through at least a part of the object, and a first electromagnetic interference signal;
detecting a second receive signal comprising at least a second electromagnetic interference signal by a first receive means of the measurement arrangement while the first receive signal is detected by the first EMAT receive transducer; and
joint processing of at least the first receive signal and the second receive signal in an interference suppression operation by an interference suppression means of the measurement arrangement,
wherein at least the first receive signal is at least partially interference-suppressed, and
wherein the first electromagnetic interference signal and the second electromagnetic interference signal are generated at least in part by a common source that is different than the electrically conducting object.

2. The measurement method according to claim 1 , wherein the second receive signal is detected by a receive means induction coil of the first receive means which is positioned on or near the surface of the object and which has at least one conductor path, wherein a coil interference signal is detected as the second interference signal.

3. The measurement method according to claim 2 , wherein the receive means induction coil used to detect the second receive signal is at least essentially identical in structure to the first receive transducer induction coil.

4. The measurement method according to claim 2 , wherein the first transmit transducer induction coil or a further induction coil of the measurement arrangement differing from the receive transducer induction coil is used to detect the second receive signal.

5. The measurement method according to claim 1 , wherein the second receive signal is detected by a line of the measurement arrangement connected in an electrically conducting manner to the object or to an earthed housing part of a housing protecting the measurement arrangement or otherwise earthed as the first receive means, wherein an earthing interference signal is detected as the second interference signal.

6. The measurement method according to claim 5 , wherein the second receive signal tapped via the line is injected into a measurement line of the measurement arrangement while maintaining a galvanic isolation.

7. The measurement method according to claim 1 , wherein at least the first receive signal and the second receive signal are fed to an analogue and/or digital, electrical and/or electronic component or to an analogue and/or digital, electrical and/or electronic circuit as the interference suppression means.

8. The measurement method according to claim 1 , wherein the first receive signal and the second receive signal are fed to a common-mode choke as the interference suppression means and are subjected to an inductive subtraction as the interference suppression operation.

9. The measurement method according to claim 1 , wherein the first receive signal and the second receive signal pass through a first amplifier stage before they are processed in the interference suppression operation.

10. The measurement method according to claim 1 , wherein the first receive signal and the second receive signal pass through an explosion protection barrier (EX barrier) of the measurement arrangement protecting a sensor area of the measurement arrangement which comprises at least the first EMAT transmit transducer and the first EMAT receive transducer before they are processed in the interference suppression operation.

11. The measurement method according to claim 1 , wherein the first receive signal and the second receive signal are subjected to a correlation analysis, wherein a correlation between the first electromagnetic interference signal and the second electromagnetic interference signal is determined.

12. The measurement method according to claim 11 , wherein a correlation analysis is carried out for at least two different frequencies depending on the frequency of the first ultrasound wave.

13. The measurement method according to claim 1 , wherein the first electromagnetic interference signal and at least the second electromagnetic interference signal are detected jointly, the first electromagnetic interference signal by the first EMAT receive transducer, and at least the second electromagnetic interference signal by the first receive means, wherein a correlation between the first electromagnetic interference signal and the second electromagnetic interference signal is determined.

14. The measurement method according to claim 11 , wherein the correlation analysis is carried out multiple times in succession and weighted correlation factors are determined on the basis of a statistical analysis of correlation factors determined by respective correlation analyses.

15. The measurement method according to claim 1 , further including the following steps:
detecting a third receive signal differing from the second receive signal and comprising at least a third electromagnetic interference signal, by a second receive means of the measurement arrangement differing from the first receive means, wherein the third electromagnetic interference signal is a coil interference signal or an earthing interference signal,
joint processing of at least the third receive signal with the first receive signal and the second receive signal in the interference suppression operation by the interference suppression means of the measurement arrangement,
wherein at least the first receive signal is at least partially interference-suppressed.

16. The measurement method according to claim 1 , wherein a second ultrasound wave is generated in the object by a second EMAT transmit transducer of the measurement arrangement which is positioned on or near the surface of the object and which has a second transmit transducer induction coil having at least one conductor path, and a second EMAT receive transducer of the measurement arrangement which is positioned on or near the surface of the object and which has a second receive transducer induction coil having at least one conductor path detects the second receive signal,
wherein, in addition to the second electromagnetic interference signal, the second receive signal comprises a second ultrasound signal resulting at least partially from the second ultrasound wave which has propagated through at least a part of the object,
wherein the first ultrasound wave is modulated with a first modulation pattern and the second ultrasound wave is modulated with a second modulation pattern so that, following the detection, a unique assignment of the first ultrasound signal to the first ultrasound wave and of the second ultrasound signal to the second ultrasound wave is enabled,
wherein both the first receive signal and the second receive signal are in each case at least partially interference-suppressed by the joint processing in

Assignees

• Rosen Swiss Ag
• Rosen 2 Holding Ag

Inventors

• Blumenstein Eduard
• Schemmann Marcel

Classifications

• H04B11/00

  Transmission systems employing ultrasonic, sonic or infrasonic waves · CPC title

• G01R31/002

  where the device under test is an electronic circuit · CPC title

• G01N29/2412

  using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]; (investigating the presence of flaws using eddy currents G01N27/90, magnetostrictive transducers B06B1/08, measuring magnetostrictive properties G01R33/18) · CPC title

• G01F1/66

  by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters · CPC title

• G01F1/667

  Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters · CPC title