The LF-U 5 is a passive near-field probe. To measure, the curved underside of the probe is positioned onto the surface of components. Field lines from other sources, which enter the probe straight or laterally, are also detected.
The near-field probe is small and handy. It has a current attenuating sheath and, therefore, is electrically shielded. It can be connected to a spectrum analyzer or an oscilloscope with a 50 Ω input. The H-field probe does not have an internal terminating resistance of 50 Ω.