Square magneto-glass current sensor based on virtual instrument

An optical current sensor based on square magneto-optic glass is demonstrated experimentally, and a corresponding VI (virtual instrument) signal processing system for both signal acquisition and analysis is established. In addition, the influence of the phase shift caused by total reflection is theoretically analyzed and numerically simulated as presented in Fig.4 of the full paper. It is revealed that the reflection phase shift is independent of the incident angle but has a relatively large effect on the linearity of the measured current. The experimental results with the measured current varying from 100A to 340A are demonstrated in Fig.7 (a); except for that the experimental values differ from the theoretical ones by a constant ratio, these results imply a good linearity of the signal processing system and are consistent with the simulations of the reflection phase shift. When this difference of a constant ratio is compensated for by a calibrating operation, the experimental values and the theoretical ones fall on the same straight line as displayed in Fig.7(b).