Time-domain calibration of field strength sensors for electromagnetic pulse (EMP) measurements

EMP (electromagnetic pulse) simulators built to test the hardening of electronic equipment against a high-intensity pulsed EMP produced by a nuclear detonation are discussed. In particular, a method for time-domain calibration of the field-strength sensors needed to carry out measurements is presented. The approach taken is to calculate the response of a simple electric and magnetic field sensor consisting of a closed circular loop (CCL) when placed in the electromagnetic field created by a small EMP simulator consisting of a transversal electromagnetic (TEM) cell. The results of measurements carried out to verify the field distribution within the TEM cell as well as the calculated sensor factor of the CCL sensor are presented. They show that the calculated sensor factor of the CCL sensor agrees reasonably well with practical measurements in an EMP field (to within 5%), making it suitable as a reference sensor to measure unknown pulsed electromagnetic fields or to compare with other sensors for which the sensor factor is unknown in the time domain.<>