1 coil measurement signal path from the lock-in to LabVIEW via GPIB
2 signal from the detection coils
3 driving signal from the lock-in to the mechanical vibrator
4 the power supply connection to the magnet
5 the power supply control signal from LabVIEW
6 the Hall-probe input to LabVIEW via the DAC
7 mechanical vibrator, ~8! electromagnet
9 magnet pole pieces
10 detection coil
11 drinking straw shaft
12 Hall probe