The Design Of Calibration System And Improvement For Atmosphere Electric Field Mill

Lightning has become an important cause to disasters in building, electricity, electronics, communication, aviation and aerospace. Therefore, real-time monitoring and early warning of lightning is particularly important, electric field mill plays an important part in this system, we can fully process the characteristic of lightning and do further study by studying the atmosphere electric field. In order to improve the reliability of electric field measurement data and the accuracy of early warning, it is very necessary and meaningful to set up a calibration system.In this article, data acquisition and control are based on SCM, the output of high-voltage source is controlled to simulate uniform electric field between the parallel plates, finally the value measured by electric field mill is sent into the PC software to compare with the theoretical value for the purpose of calibration.The electrostatic field is simulated in capacitive devices, the device is composed by two parallel circle plates which are 4 meters in diameter, the output of 100kv high-voltage source is controlled to simulate uniform electric field between the parallel plates. In this acquisition and control system, high-precision AD chips are used to do analog to digital conversion, then average algorithm was applied to do digital filter for the output voltage data to get the results, output of high-voltage source is controlled by DA chips. RS-485 is used to transmit the data to computer, it is longer in transmission distance, and has higher quality and safety.A more scientific way of calibration was designed, and also the specific procedure and the notes. Compare the measurement with the theoretical value during the calibration process, the data and result were highlighted. After preliminary analysis of electric field during the thunderstorm, the whole design was totally demonstrated.After improving the accuracy of measurement by calibration, GPS module was added to eliminate the time error due to the network delay, by reading the data from GPS module, time and location information were also transmitted by GPRS module. The electric field become more worthy of studying in lightning warning.