Use these coils to easily generate relatively accurate low-value magnetic fields. Operation is relatively straightforward: A current is supplied to the coil, the current magnitude is measured, and the magnetic field value is calculated. The coils can be used to generate both DC and AC fields. The field shape exactly follows the current waveform.

Lake Shore offers two types of Helmholtz coils:

• MH (field standards) coils, which provide small-volume fields for studying magnetic material properties or for use as a standard field coil. A calibration constant is provided, which allows the user to generate accurate field values with a known current input. The field homogeneity is specified to exist in a volume centered in the coil interior.

• FH (magnetic moment measurement) coils, which include a probe and contain stored calibration data, making them directly compatible with the Model 480 fluxmeter. As a result, little or no user inputs are required. These coils are particularly valuable when testing permanent magnets. Values such as operating flux density, operating field strength, coercive force, and residual flux density, and maximum energy product can be derived from the measured moment value.