Benefits of GMR sensors for high spatial resolution NDT applications
- Magneto resistance sensors like GMR (giant magneto resistance) or TMR (tunnel magneto resistance) are widely used in industrial applications, examples are position measurement and read heads of hard disk drives. However, in case of non-destructive testing (NDT) applications these sensors, although their properties are outstanding like high spatial resolution, high field sensitivity, low cost and low energy consumption, never reached a technical transfer to an application beyond sci-entific scope. This paper deals with benefits of GMR/TMR sensors in terms of high spatial resolution testing for different NDT applica-tions. The first example demonstrates the preeminent advantages of MR-elements compared with conventional coils used in eddy current testing (ET). The probe comprises one-wire excitation with an array of MR elements. This led to a better spatial resolution in terms of neighboring defects. The second section concentrates on MFL-testing (magnetic flux leakage) with activeMagneto resistance sensors like GMR (giant magneto resistance) or TMR (tunnel magneto resistance) are widely used in industrial applications, examples are position measurement and read heads of hard disk drives. However, in case of non-destructive testing (NDT) applications these sensors, although their properties are outstanding like high spatial resolution, high field sensitivity, low cost and low energy consumption, never reached a technical transfer to an application beyond sci-entific scope. This paper deals with benefits of GMR/TMR sensors in terms of high spatial resolution testing for different NDT applica-tions. The first example demonstrates the preeminent advantages of MR-elements compared with conventional coils used in eddy current testing (ET). The probe comprises one-wire excitation with an array of MR elements. This led to a better spatial resolution in terms of neighboring defects. The second section concentrates on MFL-testing (magnetic flux leakage) with active field excitation during and before test-ing. The latter illustrated the capability of highly resolved crack detection of a crossed notch. This example is best suited to show the ability of tiny magnetic field sensors for magnetic material characterization of a sample surface. Another example is based on characterization of samples after tensile test. Here, no external field is applied. The magnetization is only changed due to external load and magnetostriction leading to a field signature which GMR sensors can resolve. This gives access to internal changes of the magnetization state of the sample under test.…
Autor*innen: | Matthias Pelkner, Robert Stegemann, Nadja Sonntag, Rainer Pohl, Marc Kreutzbruck |
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Dokumenttyp: | Beitrag zu einem Tagungsband |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | AIP Conference Proceedings |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 8 Zerstörungsfreie Prüfung |
8 Zerstörungsfreie Prüfung / 8.4 Akustische und elektromagnetische Verfahren | |
Herausgeber (Institution): | American Institute of Physics |
Jahrgang/Band: | 1949 |
Erste Seite: | UNSP 040001, 1 |
Letzte Seite: | 10 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | GMR; Non-destructive testing; Sensor arrays; Spatial resolution |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Veranstaltung: | QNDE 2017 |
Veranstaltungsort: | Provo, Utah, USA |
Beginndatum der Veranstaltung: | 16.07.2017 |
Enddatum der Veranstaltung: | 21.07.2017 |
DOI: | 10.1063/1.5031535 |
ISSN: | 0094-243X |
ISBN: | 978-0-7354-1644-4 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 31.05.2018 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 14.06.2018 |