摘要 |
The invention concerns a method of measuring an alternating current (IA) in a conductor (2), the method calling for the plane of polarization of linearly polarized light to be rotated through a measuring angle (ALPHA) in a Faraday element (3) surrounding the conductor (2). This light with rotated polarization is divided into two light signals (LS1, LS2) with planes of polarization at right angles to each other, and the corresponding electrical signals (S1, S2) produced by conversion in optoelectric converters (12, 22) are split into their direct signal components (D1, D2) and their alternating signal components (A1, A2). The invention calls for the quotients5 ((A1-A2)/(Al+A2) and ((D1-D2)/(D1+D2)) of the differences and sums of the alternating signal components (A1, A2), as well as of the direct signal components (D1, D2) to be determined. A temperature-compensated measuring signal (SA) is derived from the quotients of the direct signal components ((D1-D2)/(D1+D2)) and the quotients of the alternating signal components ((A1-A2)/(A1+A2)).
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