Research And Application Of Spherical Electric Field Sensor Measurement System

Measurement of electric field has important applications in many scientific research and engineering technology fields. No matter to manufacture and safe operation of power equipment, or environmental monitoring and other applications is very significant that can realize real-time and accurate monitoring the size of the electric field. The probe size, electrode material, electrode coupling and survey crew and so on that have effect on the meter precision when sensors are measuring electric field. Therefore, making analysis on distortion quantity size caused by sensor probe in field, designing optimized sensor probe structure, researching a remote acquisition measurement data of electric measuring system, are important to improve the accuracy of electric field measurement system.The paper mainly analyzes that the electric distortion quantity caused by spherical probe in homogeneous electric field environment,using method of separation of variables . It also does simulation analyses on distortion field which is caused by different probe size, electrode materials and electrode coupling of measurement electrode. Thus it also makes optimized design on sensor probe and uses influence factors matrix method to check the electric field, to improve accuracy of measurement of the system.This device adopts American microchip company PIC18F4420 microcontroller as the central processor for A/D conversion, data processing, etc. The weak signal amplification is amplified by using instrumentation amplifier INA128 chip produced by Texas Instruments. And the data communication is through TC35i module produced by Siemens Company. In software MPLAB IDE is used as the development platform, mainly designing data acquisition, data processing and data communication module, and calibrating the measuring data in data processing. Finally, in order to enhance reliability of the system, corresponding software anti-interference research has been done.According to the requirement of GB-T12720-1991, through the use of electric field least-square method after fitting to the measured value, the test that under the design of homogeneous electric field produces device shows when sampling capacitance is 350pF that nonlinear error of the system was about 6.68%, in power frequency electric intensity value is less than 12kV.m^-1 inside, The external electric and sensor system output has good linearity, that can satisfy the practical needs of the project.