Helmholtz Coils
A Helmholtz coil is actually a pair of specially constructed coils mounted a fixed distance apart on a common base. Current passed through the coils produces an extremely uniform magnetic field in the space between them. For the measurement of magnets, the coils are used in a different manner – they are connected to an integrating fluxmeter, which gives an accurate indication of the overall strength of the magnet when it is withdrawn or rotated a half-turn. If a gaussmeter is used for this purpose, many measurements may have to be made because of local variations of magnetic strength. A Helmholtz coil, on the other hand, measures the entire magnet at once, in a fast, reliable, and easy manner. For this reason, Helmholtz coils are ideal for quality checking of magnet parts after they have been magnetized.
