line impedance

When viewed from the end of the power line such as a commercial power outlet toward the power source side, this is the impedance. When measuring conducted noise transmitted through the power line, if the line impedance is low, the noise appears lower than it actually is, and if the impedance is high, the noise appears higher than it actually is. This becomes a factor causing error in noise measurements. Therefore, to eliminate measurement errors caused by line impedance, a Line Impedance Stabilization Network (LISN) is used.