Study on magnetic field measurement around power lines using ordinary materials with Faraday effect

The measurements of electric field, voltage, magnetic field and current are often required to study high voltage, large current or other electromagnetic phenomena. As one of the methods for that, there is an optical method using electro- or magneto-optic effects. Taking up Faraday effect as an example, and using water as a Faraday material, the magnetic fields around a miniature power lines in the laboratory could be measured. From those results, it seemed that the magnetic field around real power lines, where the current of about 1000A flows, can be measured by using air as a Faraday material.