T. Hetkämper, K. Koch, L. Claes, and B. Henning, “Phase-preserving methods to visualise ultrasonic fields with schlieren imaging,”10.1515/teme-2022-0112__tm - Technisches Messen, vol. 90, no. 2, pp. 103–112, 2023, doi:10.1515/teme-2022-0112 .
LibreCat: /record/37543
DOI: 10.1515/teme-2022-0112

D. Dreiling, D. Itner, T. Hetkämper, C. Birk, H. Gravenkamp, and B. Henning, “Improved determination of viscoelastic material parameters using a pulse-echo measurement setup,”10.5162/SMSI2023/P59__in SMSI 2023 Conference, Nürnberg, 2023, pp. 394–395, doi:10.5162/SMSI2023/P59 .
LibreCat: /record/45205
DOI: 10.5162/SMSI2023/P59

T. Hetkämper, K. Koch, M. Webersen, and L. Claes, “Application-based learning of signal analysis methods with the help of a graphical open-source software,”10.21427/159K-G445__presented at the SEFI 2023 Annual Conference, 2023, doi:10.21427/159K-G445 .
LibreCat: /record/47138
DOI: 10.21427/159K-G445

T. Hetkämper, L. Claes, and B. Henning, “Vorzeichenrichtige tomographische Rekonstruktion von Ultraschallfeldern mit Hilfe der Schlierentechnik,”10.1515/teme-2023-0069__tm - Technisches Messen, vol. 90, no. , pp. 49–54, 2023, doi:10.1515/teme-2023-0069 .
LibreCat: /record/48053
DOI: 10.1515/teme-2023-0069

T. Hetkämper, Visualisierung von Ultraschallfeldern mittels Schlierentechnik und fraktionaler Fouriertransformation. Workshop “Messtechnische Anwendungen von Ultraschall”, Drübeck, 2022.
LibreCat: /record/6561

T. Hetkämper, L. Claes, and B. Henning, “Schlieren imaging with fractional Fourier transform to visualise ultrasonic fields,” presented at the 21. ITG/GMA- Fachtagung Sensoren und Messsysteme 2022, Nürnberg, 2022.
LibreCat: /record/31331

L. Claes et al., “Measurement procedure for acoustic absorption and bulk viscosity of liquids,”10.1016/j.measurement.2021.109919__Measurement, Art. no. 109919, 2021, doi:10.1016/j.measurement.2021.109919 .
LibreCat: /record/22925
DOI: 10.1016/j.measurement.2021.109919

T. Hetkämper, D. Dreiling, L. Claes, and B. Henning, “Tomographie des Schallfelds von Ultraschallwandlern mittels Schlierentechnik,” presented at the DAGA 2021 - 47. Jahrestagung für Akustik, 2021.
LibreCat: /record/25880

T. Hetkämper, M. Krumme, D. Dreiling, and L. Claes, “A modular, scalable open-hardware platform for project-based laboratory courses in electrical engineering studies,” in SEFI 48th Annual Conference Proceedings - Engaging Engineering Education, Enschede, 2020, pp. 1309–1313.
LibreCat: /record/19502

L. Claes, C. Steidl, T. Hetkämper, and B. Henning, “Estimation of acoustic wave non-linearity in ultrasonic measurement systems,”10.48550/arXiv.2001.05708__arXiv.org, 2020, doi:10.48550/arXiv.2001.05708 .
LibreCat: /record/15489
DOI: 10.48550/arXiv.2001.05708
arXiv: 2001.05708

T. Hetkämper, L. Claes, and B. Henning, “Evolutionary algorithm for the design of passive electric matching networks for ultrasonic transducers,” in 2019 International Congress on Ultrasonics, Bruges, 2019.
LibreCat: /record/16076
DOI: 10.1121/2.0001110