Steve, your point. He does indeed say that, my question remains what is he trying to measure that requires direct mounting of the micro on the rotor.
Amost all parameters can be measured remotely, and if direct measurement is needed then mount the sensor set needed and transmit data to a stationary reciever.
Sensors are designed with hostile environments as a given as are some remote tramsmitters so by selection the optimum setup can be achieved . If interferance is a problem the signal can be encoded right at the sensor (the point of least possible interferance) and then transmitted to the remote reciever.
Also adding mass to the rotor will upset the balance so this setup must be installed before balancing
and can not be altered significantly after (no mass or mass distribution changes ) Terry