A Method to Measure Magnetic Fields Accurately Using Ampere´s Law

A proposed method to measure magnetic fields is described, and a simple demonstration of the new method has been performed. A derivation of the equation used to calculate the field is presented, and some ofits implications are discussed. The objective of further experiments is to apply the technique to the measurement of the gyromagnetic ratio of the proton (¿p) to an accuracy near 1 part in 108, using a precision solenoid whose departures from ideal are small.