The Fiber Optic Transmission And Intelligence Testing For The Signal Of Electric Field Sensing

The test of the electric field intensity is always very important in electronics and electro-techniques. The traditional measure equipment of the electric field may change the field so that measure precision and safety may be affected. But these shortcomings can be conquered by the techniques of fiber optic sensing.The system of fiber optic transmission and intelligent test for the signal of electric field sensing is studied. In the system, the especial requests are considered. The system has little influence to the electric field and has high isolative capability, moreover, it has many advantages such as high delicacy, high anti-jamming capability.The pulse frequency-intensity modulation technique of analog modulation is used in the system. In the foreside of the system, the signal of electric field sensing is changed into the signal of variable frequency, then the signal of variable frequency modulates the light source, which produces the signal of light pulse varying with the signal of variable frequency; the modulated light signal is transmitted though the optical fiber, in the sink of the system, the light signal is transformed into electric signal, the test, process, display of the electric signal is completed by the microcontroller.The result of experiment displays the test relative error of the signal from 2mv to 5v is not more than 5%, the test precision achieves request on the whole. The system is energy-saving and has small volume. Because microcontroller is used to process and control the signal, the function of intellectualized system such as setting parameter, correcting temperature and nonlinearity error.Having improved the circuit, the system can automatically change the test range to minimize the interference to the small signal. Based on the same system, the vector signal of electric field sensing can also be tested by use of time division multiplexing.In the practical applications, when the variable parameters such as temperature, stress, current, are transformed into the variety of the voltage, these parameters may be sensed, tested by the system safely with precision request. Therefore, the system has high practicality.