Calibration Method Research for High Power Transient Electromagnetic Field Sensor

Abstract

In recent years, the requirements for high power transient electromagnetic field measurement have gradually increased. The calibration is the most critical part in accurate measurement. Therefore, the need for high-accuracy calibration of high power transient electromagnetic field sensors, including amplitude calibration and frequency bandwidth calibration, has become increasingly urgent. However, IEEE Std 1309-2013 does not contain a specific calibration method for high power transient electromagnetic field sensors. In this paper, by analyzing the TEM cell and the monocone TEM cell, combined with the advantages of these two standard electromagnetic field generating devices, these two TEM cells are selected as the calibration devices for the transient electromagnetic field sensor. Unfortunately, the size of TEM cell, constrained with the calibration accuracy, decreases its frequency bandwidth. And the low frequency of monocone is unavailable due to its narrow time window. As a viable solution, the TEM cell is used for amplitude calibration, meanwhile the monocone TEM cell is used for frequency bandwidth calibration. Moreover, a practical and operational calibration process is proposed in this paper. The process includes the obtainment of the calibration coefficient $K$ in the amplitude calibration, as well as the determination method of the sensor's upper frequency in the bandwidth calibration.