FIBER OPTIC CURRENT PROBE

SPEED, ACCURACY AND SAFETY ARE OFFERED BY A NON-CONTACT, ALL DIELECTRIC CURRENT MEASUREMENT TECHNIQUE UTILIZING POLARIZED LIGHT AND FIBER OPTIC CABLES MADE FROM MATERIALS WHICH EXHIBIT THE FARADAY EFFECT. THE FARADAY EFFECT MANIFESTS ITSELF BY THE ROTATION OF THE PLANE OF VIBRATION OF PLANE POLARIZED LIGHT THAT PASSES THROUGH THE MATERIAL IN A DIRECTION PARALLEL TO AN APPLIED MAGNETIC FIELD. THE AMOUNT OF ROTATION OF THE PLANE OF VIBRATION IS RELATED TO THE STRENGTH OF THE MAGNETIC FIELD WHICH IN TURN CAN BE RELATED TO THE CURRENT IN A CONDUCTOR. THUS ONE MEASURES THE ROTATION ON THE PLANE OF VIBRATION WHICH YIELDS DIRECTLY THE MAGNETIC FIELD STRENGTH AND INDIRECTLY THE CURRENT. THREE ELEMENTS COMPRISE THE MEASUREMENT SYSTEM: A TWO FREQUENCY LASER, A FIBER OPTIC LOOP(S), AND A DETECTORAND PROCESSOR MODULE. IN COMBINATION THESE ELEMENTS PROVIDEFOR GENERATION OF TWO ORTHOGONALLY POLARIZED SOURCES OF LIGHT, THE TRANSDUCING FIBER OPTIC LOOP, AND A DETECTOR/ ELECTRONICS MODULE WHICH DETERMINES THE RELATIVE PHASE BETWEEN THE TWO ORTHOGONAL BEAMS. THE SYSTEM OFFERS SPEED, ACCURACY WITH HIGH PRECISION AND A WIDE DYNAMIC RANGE TO THEPROBLEM OF CURRENT MEASUREMENT.