How to measure contactlessly position of a spinning miniature cylindrical magnet?

you say diametrically magnetised meaning north pole at 0 degrees and south at 180 degrees and spinning so to that north and south swap places?

what's the minimum rate of spin?

will it spin backwards, if it does do you need to know it's going backwards?

do you need angle information?

In what environments must the sensor operate, hand-held or worn ....

are momentary failures acceptable? how often and for how long?

external to the implantee?

so you have to cancel that field out before you can read its position, any nearby magnetic materials are going to muddy the water no matter how finely you tune the sensor.

...

If you read the thread carefully, you will find

"Up to 300 rpm." I take that to mean no lower bound. "Typically, the measurement is performed between from 300 to 1 Hz."

"The rotor is excited by an external rotating magnetic field generator composed of a 3-Phi coil ..." Hence the rotor moves whichever way the field rotates.

"... this rotor is a part of an implanted biosensor."

Jerry

usenet arriives here delayed by a paticularly vile pieco of software called "leafnode" I have to ask for each article and then wait and ask again a few hours later... (a process I have recently maganed to automate)

at the time I posted that that info wasn't availablew to me. on the other hand sometimes I'm ignorant and sometimes just mistaken.

Bye. Jasen