| 摘要 |
<p>PURPOSE:To simplify the structure of an ammeter for measuring a large current while enabling not only measurement in a state not contacted with a current supply circuit but also remote monitoring without receiving electromagnetic induction at all, by utilizing a magnetic fluid and an optical fiber. CONSTITUTION:A non-magnetic container 10 is provided so as to surround a cable 20 directed to a vertical direction and a magnetic fluid 22 is introduced into the container 10 while pairs of light transmitting fibers 30 and light receiving fibers 40 are attached to said container 10 so as to slightly differentiate the heights thereof. When a current is flowed to the cable 20 rising so as to pierce through the bottom of the container 10 in an air-tight state, the magnetic fluid 22 crawls up along the cable 20. Because the magnetic fluid 22 is impervious to light, the light 52 emitted from each of the light transmitting fibers 30 does not reach each of the light receiving fibers 40 present at the part equal to or lower than the height (h) where magnetic fluid 22 crawled up. Therefore, by investigating the light receiving fibers 40, the magnitude of a current I can be known.</p> |
