The LI-220A Line Impedance Stabilization Network (LISN) is in full compliance with both CISPR 16-1-2 and ANSI C63.4. It provides the necessary measurement platform for performing power line conducted emissions compliance testing as required by most worldwide standards for commercial products. The LI-220A performs each of the following functions during the measurement:

• Provides a defined, stable impedance across the measurement frequency range;
• Isolates the EUT and measurement circuit from the power source, thereby minimizing its influence on the measurements; and,
• Couples the disturbance voltages to the coaxial measurement port (either directly, or through a transient limiter w/10 dB attenuation, depending on switch position), for connection to the measuring instrument.

This LISN uses air-core inductors to prevent saturation and permeability variation. The mounting plate of the LI-220A is left unpainted in order to facilitate connection to earth ground in its installation, which is essential due to high leakage current.