Figure 2.

Signal acquisition and excitation cancellation with benchtop MPS device: (a) Axial excitation field profile (blue symbols) inside the TxC measured by a small probing coil (inner diameter: 1.5 mm, length: 1.7 mm, four layers, 68 turns). The range in which the excitation field deviates from the maximum value by less than 5% is highlighted in blue. The probing coil was further used to generate a reference signal to determine the sensitivity profile of the receive coil (red). (b) Measured induced voltage (1st harmonic) at different positions of the RxC within the TxC. (c) Measured spectrum of an empty flow cell (averaging 0.2 s, with background correction) at 1 mT (red symbols) and 50 mT (blue symbols) excitation field strength with (left, squares) and without (right, circles) BSF. Note, the connecting lines are a guide to the eye.