PURPOSE: To maintain sufficient sensitivity and output stability by using a garnet type ferrite polycrystalline body which has specific characteristics as an optical element.
CONSTITUTION: This magnetooptical sensor is made of the garnet type ferrite polycrystalline body which has characteristics such as a 1deg/cmOe Verdet's constant, ≥100μm thickness, ≥10% light transmissivity, and a ≤±1.0% temperature characteristic for magnetic field detection at -20 - +60°C and also has ≤1/10,000 magnetic field detection accuracy and is expressed as BixGdyYzFe5 O12(x+y+z=3) as an optical element. In this case, bismuth substitute rare earth iron garnet polycrystal which has sufficient sensitivity and output stability and is uniform in magnetooptical characteristics is obtained as the magnetooptical element of a magnetooptical field sensor for ground-fault and short-circuit detection for power distribution.
ASAI EMI
OKAMOTO KATSUNORI
