Research Of The Current Detection Based On Optical Transmission Of Magnetic Fluid

Magnetic fluid is a new type of magnetic materials, it is a kind of stable colloidal suspension which contains ferromagnetic particles uniformly distributed and has a property of liquid flow, so it possesses a variety of unique characteristics. Including the thermal lens effect, magneto-optical effect, tunable refractive index and magneto-chromatic effect. Furthermore, magnetic fluids have played a huge role in many areas, including electrical, mechanical, medicine, physics, chemistry, etc.This paper establishes the microcosmic model to study the optical character of the magnetic fiuids films by the Monte Carlo method based on the microsturctures have been simulated. The model simulates the spread process of light in the magnetic fluids film, analysis the influence factor to the spread process and computes the spectral transmittivity statistically. Some factors of affecting the spectral transmittivity of magnetic fluids film are investigated, such as the film thickness, the nanoparticle concentration, nanoparticle diameter and strength of applied magnetic field. Furthermore, the relationships between the microsurtcture and the optical characteristic of the magnetic fluids film are investigated.In this paper, a type of current measuring system using ferrofluid films has been studied. The basic operation principle and design of the novel sensor is based upon the field-dependent transmitivity. When a thin film of ferrofluids is subjected to a magnetic field applied which is perdicular to the plane of film, a portion of magnetic particles is condensed out from the initially monodispersed magnetic fluid and forms magnetic chains, then the optical transmitivity of the ferrofluid changes. The sensitivity and response time can be tailored during fabrication to suit the application by changing the concentration, liquid carrier or changing the configuration of the transducer cell.Experiments show that the main advantage of this method in comparison with the optical current transformer on Faraday effect and the conventional electromagnetic current transformer avoids problems in the low SNR and the high-volatge isolation.