in Mitaka
I measured the magnetic flux of a prototype coil magnet actuator for TMS vibration isolation system.
I used a tesla meter "MODELbTM-801" by KANETEC.
The magnets made by Neo Mag were used and the magnetic flux of this magnet was about 556 mT.
[Result]
The magnetic flux inside the yoke (overhang part) was about 115 mT.
This value is smaller than the designed value about 170 mT.
The difference seems to be leakage of flux.
Then I measured leakage of the magnetic flux from the surface.
upper surface
Measured at 3 points (screw position)
left & right side was about 13 mT (magnetic pole:S).
center was about 28 mT (N).
There were zero cross position about 2.3 mm from the side edge.
The leakage from bottom surface were about 35 mT (S) both left and right.
This value was measured around the center of surface.
At the edge, the flux was much larger about 80 mT.
The detail will be uploaded to JGWdoc.
Anyway, the magnet flux inside the yoke were smaller than designed.
This is caused by leakage from other surface and this leads to the less efficiency of the actuator.
The estimated efficiency is 6.95 N/A, however, the actual value is 5.0 N/A.
