In standardized emissions compliance measurements, the emission level of an equipment under test (EUT) is measured, after which compliance with the associated limit is determined. The measured emission level is an approximation of the true level due to uncertainties induced by various contributors. In emissions compliance testing, major relevant contributors related to the EUT or to the measurement procedure happen to be unspecified and no quantitative information is available about their values, for example, operator skills, quality system of the laboratory performing the test, environmental conditions, production tolerance of the EUT model, operation of the EUT, and so on. This document concentrates on the measurement instrumentation uncertainty, which is a subpart of the total uncertainty of the measurement, and it includes only the effects of those contributors that are related to the measurement instrumentation. This application guide provides methods for determining the uncertainty of measurement for electromagnetic interference (EMI) measurement results. This guide provides information on the application of Type A statistical evaluations. For Type B applications, this guide also provides information on where to obtain specified published information that can lead to an evaluation of uncertainty. The current document provides information on the range 150 kHz to 30 MHz for conducted emissions on main lines, and 30 MHz to 18 000 MHz for radiated emissions measurements.