Высокочувствительный датчик напряжения магнитного поля с феррамагнитной жидкостью

Магнитные (и магнитодиэлектрические) жидкости представляют собой искусственно сформированные и особым образом структурированные среды, обладающие уникальными электрическими и магнитными свойствами. Под такими свойствами следует понимать особые значения физических параметров среды: диэлектрической ? и магнитной ? проницаемости, пространственной структуризации, зависящей от размера и формы магнитных и диэлектрических частиц, наличия возможности управления параметрами среды в результате внешних воздействий. Высокая подвижность магнитных частиц в жидкости обеспечивает их сильную чувствительность к слабым магнитным полям и дает значительное преимущество по сравнению с твердотельными аналогами. Всестороннее изучение магнитной жидкости позволит конструировать сенсоры магнитного поля.Magnetic (and magnetodielectric) fluids are artificially formed and specially structured media with unique electrical and magnetic properties. Such properties should be understood as special values of the physical parameters of the medium: dielectric ? and magnetic ? permeabilities, spatial structurization, depending on the size and shape of magnetic and dielectric particles, the possibility of controlling the parameters of the medium as a result of external influences. The high mobility of magnetic particles in the fluid ensures their strong sensitivity to low magnetic fields and gives a significant advantage in comparison with solid-state analogs. A thorough study of the magnetic fluid will allow the construction of magnetic field sensors

A Magnetic Field Sensor Based on a Magnetic Fluid-Filled FP-FBG Structure

Based on the characteristic magnetic-controlled refractive index property, in this paper, a magnetic fluid is used as a sensitive medium to detect the magnetic field in the fiber optic Fabry-Perot (FP) cavity. The temperature compensation in fiber Fabry-Perot magnetic sensor is demonstrated and achieved. The refractive index of the magnetic fluid varies with the applied magnetic field and external temperature, and a cross-sensitivity effect of the temperature and magnetic field occurs in the Fabry-Perot magnetic sensor and the accuracy of magnetic field measurements is affected by the thermal effect. In order to overcome this problem, we propose a modified sensor structure. With a fiber Bragg grating (FBG) written in the insert fiber end of the Fabry-Perot cavity, the FBG acts as a temperature compensation unit for the magnetic field measurement and it provides an effective solution to the cross-sensitivity effect. The experimental results show that the sensitivity of magnetic field detection improves from 0.23 nm/mT to 0.53 nm/mT, and the magnetic field measurement resolution finally reaches 37.7 T. The temperature-compensated FP-FBG magnetic sensor has obvious advantages of small volume and high sensitivity, and it has a good prospect in applications in the power industry and national defense technology areas

A Magnetic Field Sensor Based on a Magnetic Fluid-Filled FP-FBG Structure

Based on the characteristic magnetic-controlled refractive index property, in this paper, a magnetic fluid is used as a sensitive medium to detect the magnetic field in the fiber optic Fabry-Perot (FP) cavity. The temperature compensation in fiber Fabry-Perot magnetic sensor is demonstrated and achieved. The refractive index of the magnetic fluid varies with the applied magnetic field and external temperature, and a cross-sensitivity effect of the temperature and magnetic field occurs in the Fabry-Perot magnetic sensor and the accuracy of magnetic field measurements is affected by the thermal effect. In order to overcome this problem, we propose a modified sensor structure. With a fiber Bragg grating (FBG) written in the insert fiber end of the Fabry-Perot cavity, the FBG acts as a temperature compensation unit for the magnetic field measurement and it provides an effective solution to the cross-sensitivity effect. The experimental results show that the sensitivity of magnetic field detection improves from 0.23 nm/mT to 0.53 nm/mT, and the magnetic field measurement resolution finally reaches 37.7 T. The temperature-compensated FP-FBG magnetic sensor has obvious advantages of small volume and high sensitivity, and it has a good prospect in applications in the power industry and national defense technology areas