A method to calculate uncertainty of LISN conducted measurements

A method to calculate uncertainty of a conducted test that uses line impedance stabilization networks (LISN) and tunable receivers is presented. The measurement data obtained when characterizing the input impedance of LISNs (artificial mains network) and the calibration of a receiver, normally available at an EMI test facility as part of the quality system, is used to calculate uncertainty. The uncertainty is determined using a tuned receiver and also when a receiver is "stepped" at 9 kHz increments across the spectrum. The resultant calculations are consistent with engineering experience and provides insight on what and where to incorporate improvements in existing operations.