Tolerance Values and the Confidence Level for High-Altitude Electromagnetic Pulse (HEMP) Field Tests

This paper discusses tolerance values and confidence levels for high-altitude electromagnetic pulse (HEMP) field tests. An HEMP simulator provides the HEMP environment with various degrees of completeness. Deviations from the ideal waveform occur due to the simulator structure and concept. In this paper, we review tolerance values for pulse parameter specified in civil and military standards. The impact of the tolerated deviations on the test objective will be discussed. In the second part, we stress the aspect of how an HEMP test must be performed to provide sufficient confidence in the HEMP survivability of the system under test. This part starts with a brief description of a usual HEMP test setup and test procedures. Characteristics of the test procedure as well as the typical behavior of systems under tests are analyzed with statistical methods. Based on the statistical analysis, we define a confidence level, a measure of the confidence in the test result.