31. When the external field is removed, the remanent magnetization can recover to a value close to its original. 32. Unfortunately, the small magnitudes of nuclear magnetic dipoles also makes them less inclined to align to external fields . 33. A permanent magnet in such a field will rotate so as to maintain its alignment with the external field . 34. The Ramsey Bord?interferometer provides the potential for improved frequency measurements in the presence of external fields or rotations. 35. Active current feedback may also be employed, such that the sense winding is driven to counteract the external field . 36. For alkynes the most effective orientation is the external field in parallel with electrons circulation around the triple bond. 37. Specifically, an excited atom will act like a small electric dipole which will oscillate with the external field provided. 38. On the other hand, the direction of current induced by external fields is only dependent on the direction of winding. 39. The associated electronics use this fact to create a signal exactly at the frequency that corresponds to the external field . 40. This helps to counter inherent non-linearity between the applied external field strength and the flux gated through the sense winding.
