With the global proliferation of mobile phones, the public has become increasingly concerned about the effects of electromagnetic fields on health, including the fields emitted by electrical household appliances and other electronic devices. International bodies have standardized the exposure limits to safeguard users from these possibly high electromagnetic fields. In order to appropriately evaluate possible exposure hazards by numerical methods, it is necessary to accurately describe the magnetic field associated with the electrical appliances. This thesis deals with a new numerical model (equivalent source model). This model enables the reproduction of complicated inhomogeneous magnetic field characteristics associated with practical electrical appliances with a complete three-dimensional representation of the magnetic field vectors (field components and directions) for the purpose of validating the inhomogeneous magnetic field dosimetry at low and intermediate frequency ranges.