The broadband immunity test system NSG 4031 has been designed for testing in accordance with IEC / EN 61000-4-31. It contains a white noise generator with four different band filters to allow band limited testing as may be required in future product standards. The internal power meter are capable to show the forward power as well as the VSWR of the connected setup. The three front panel inputs allow an easy test level setting procedure. The internal power amplifier with more than 80 Watts output power allows test levels 1 to 3 as given in table 1 of IEC / EN 61000-4-31 also including an optional 2 dB attenuator which can be used in case of severe EUT mismatch. Due to the powerful and easy to use firmware, the NSG 4031 is independent from an external PC and control software.