What is an LISN?
LISN stands for Line Impedance Stabilization Network. Basically, it’s an instrument used to measure the base radio frequencies of other devices by isolating the radio frequency of the power input. By providing a precise impedance to the power input of the EUT (equipment under test), the LISN gets repeatable measurements of the noise present at the LISN measurement port for the EUT. On top of isolating the unwanted RF (radio frequency) signals from the power source, LISN’s can be used to forecast conducted emission for diagnostic and pre-compliance testing.
Functions of a Line Impedence Stabilization Network
The LISN serves three main purposes:
LISN Calibration at Novastar
Because they are used for different tests and frequency ranges at different operating voltage levels, there are various types of LISN’s. In general, the anticipated inductance of the power line for the intended installation of the EUT plays a role in identifying the correct type of LISN needed for testing. When testing, it’s important to account for the operating environment for the types of equipment covered by each standard.
Because LISN testing is so complex and precise, it’s important that devices are correctly calibrated. NovaStar’s Calibration laboratory can now test and calibrate various LISN technology with the addition of an LISN Test Chamber, also known as a Faraday cage (named after the English scientist who invented them in 1836). Our technicians run tests in an electronically isolated environment inside an 8’ x 8’ room within the chamber to provide transmission, reflectance and impedance data for LISN’s from 5Hz to 3GHz.
The results of the calibrations are in accordance with CISPR25:2008 specifications and performed using ANSI C63.4-2014 methods.
So if your lab requires calibration of your LISN’s, NovaStar Calibration now provides this service. Instruments can be shipped to NovaStar or picked-up and delivered for free in southern Michigan and northern Ohio. NovaStar provides a one week turn around to assure your LISN works accurately and is back in service quickly.
