Schmitz, B. Alomari, K.Alomari. Knobloch, J. Kugeler, O. Köszegi, J.M. Tamashevich, Y. JACoW Geneva, Switzerland 978-3-95450-182-3 10.18429/JACoW-IPAC2017-MOPVA050 English 975-977 MOPVA050 Contribution to a conference proceedings 2017 2017-05 http://dx.doi.org/10.18429/JACoW-IPAC2017-MOPVA050 http://jacow.org/ipac2017/papers/mopva050.pdf Flux trapping is the major contribution to the residual resistance of superconducting cavities. In order to gain a better understanding of the mechanisms involved and aiming at an eventual minimization of trapped flux, a measurement setup based on AMR sensors was devised that allows for monitoring the magnetic field vector at various positions near the cavity surface. First results of the efforts are presented.