| 摘要 |
<p>PURPOSE:To obtain a measuring device which is small-sized and has high sensitivity, by providing a groove of a right angle direction to an electric conduction direction of an electric conductor, on the electric conductor, storing a photocurrent sensor in this groove, and also providing a shield having almost the same shape as the external form of the electric conductor, on the groove. CONSTITUTION:When a current flows to a circular electric conductor 2 in a cylindrical metallic vessel 1 into which SF6 is charged, a magnetic field is generated in h circumferential direction of the electric conductor 2, and its intensity becomes larger as it comes close to the surface of the electric conductor. Accordingly, when a photocurrent sensor 4 is fitted to a position close to a bottom surface 3a of a groove 3 provided on a side 2a of the electric conductor 2, a magnetic field can be detected with high sensitivity. Light which is modulated in accordance with intensity of the magnetic field by this sensor 4 is sent to a processing circuit by fibers 6, 8, is converted to an electric quantity, and a current of the electric conductor 2 is measured. On the other hand, a shield 5 is placed so as to close up the groove 3 by making its surface 5a coincide with the side 2a of the electric conductor 2, therefore, the concentration of an electric field by the groove 3 is lightened.</p> |
