Electric current measuring device

Abstract

Abstract PURPOSE: To enable temperature correction easily, by detecting both the Farady rotation angle and temperature with the same substance, by applying the change in the photo absorption of the Farady rotating material itself. CONSTITUTION: The Farady rotation material 11 closed to the power line 1 is located between the polarizer 12 and the polarized separation prism 13, this is led to the low voltage side on ground by using the rod lenses 14, 15 and optical fibers 16W18, and by using the two types of laser light sources 19, 20 in wave lengths λ 1 , λ 2 , and the photodetectors 21W24, and dichroic filter 25 in λ 1 incoming and λ 2 transmission, the photo signal each wave length is detected. The Farady rotation angle θ is expressed as θ=K 1 (I 1 -I 2 )/(I 2 +I 2 ), where the optical fiber outputs of each component as I 1 , I 2 . K 1 is a proportional constant. Further to the light in λ 1 , the Farady rotation is made similarly, but the entire transmitted output (J 1 + J 2 ) is the amount changed only to the temperature T and from this, temperature detection is made. The signal relating to θ and T is given to the operation processor 28 for temperature correction and final current value is calculated. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Tetsuo Taniuchi
• 👤 Akimoto Serizawa
• 👤 Yoshinobu Tsujimoto
• 👤 Osamu Kamata

Bibliographic Details