Method and system for measuring an electric current with two light signals propagating in opposite directions, using the Faraday effect

US5844409A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Thomas Bosselmann · Erlangen, DE
• Peter Menke · Erlangen, DE

Key dates

• Filing date: Apr 1, 1996
• Grant date: Dec 1, 1998
• Expiry date: Apr 1, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R15/246
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method and system for measuring an electric current in a current conductor, two opposing light signals are transmitted through a Faraday element surrounding the current conductor and, after the passage through the Faraday element, are split, respectively, into two partial light signals. From these partial light signals, an intensity-normalized signal is derived for each partial light signal. Provision is made of a Faraday element having a negligible circular birefringence, and a signal processing unit for deriving a vibration-independent and temperature-independent measured signal.