Measurement of electric and magnetic fields

A project was initiated to study power frequency electric and magnetic fields that exist in Canada. The main objective of the study was to produce a compendium of electric and magnetic field levels that exist in Canada, and to characterize and classify the sources of electric and magnetic fields. Typical electric and magnetic field levels were measured around generating plants, substations, transmission lines, distribution lines, residences and workplaces. Protocols were developed so that a consistent set of data could be collected, and so that sufficient detail could be captured for a thorough analysis. Generating plants were found to exhibit the widest range of magnetic field levels, from 0.02 to 250 microtesla, however had low electric field levels. Electric fields tend to be highest in substations, due to lower clearances of energized bus-work to the ground. Transmission lines had higher magnetic fields than substations and distribution lines. Characterization of distribution lines was difficult due to a wide range of configurations, however in general magnetic fields are lower than near transmission lines. A wide range of magnetic fields were found in residences, but tended to be lower than those found in workplaces. Appendices describe data collection protocols and database structure. Eight separate abstracts have been prepared for this report. 4 refs., 29 figs