The Belling & Lee Y20172 LISN (5 µH) for Def Stan 59-411 is a Single Phase LISN. The Belling & Lee Y20172 LISN is predominantly used for Conducted Emissions testing, being utilised by placing it between the power supply and EUT to accurately measure the interference that the EUT is emitting at its supply input.

Where would this be used? The Belling & Lee Y20172 LISN is used to supply the connected equipment with a known, reliable impedance and isolating the equipment from the power source, preventing external noise from interfering with measurements.