To obtain a measurement value wherein linearity error is small in a wide dynamic range, by inserting a current sensor into core gap part of a core which a wire penetrates, and performing correction calculation process to the output value from the current sensor.
A sensor part 4 is provided with a ferromagnetic core 1 which a wire 2 penetrates, an optical magnetic field sensor 6 which is inserted into a core gap part 3 of the core 1, and an optical fiber 7 which carries the optical output of the sensor 6. A measuring part 5 is provided with a photo transducer 8 connected with one end of the optical fiber 7, an A/D converter 9 connected with the photo transducer 8, and a correction calculation processing part (CPU) 10 connected with the A/D converter 9. When a current flows through the wire 2, a magnetic field is generated, detected by the sensor 6, and converted to a light, which is outputted in the optical fiber 7. The light is converted to an electric signal by the photo transducer 8. The electric signal is subjected to A/D conversion 9, and inputted in the CPU 10 in which correction calculation process is performed.
HIRANO YUICHI
MURATA HIROSHI
