The magnetic field distributions in compound inductors of different conditions are measured and analyzed using small coil method.

At present there are many methods to detect the inter-turn shorted-circuit fault of turbo-generator rotor windings. The air-gap detection coil monitoring method is effective and used widely.

Three test methods, including two-accelerometers method, four-accelerometers method and geomagnetic induction coil method, for measuring rocket rotation angle are put forward in this paper.