Line Impedance Stabilisation Network (LISN)

A Line Impedance Stabilisation Network (LISN), also known as an Artificial Mains Network (AMN), is a low-pass filter device placed between an AC or DC power source and the Equipment Under Test (EUT). It creates a stable, standardised electrical environment for measuring the amount of RF noise a device “injects” back into the power grid.

Why Choose a LISN?

Standardised Impedance: Power grids vary by building and location; a LISN provides a constant 50Ω (or 5µH / 50µH) impedance, ensuring your EMI measurements are repeatable regardless of where you test.

Noise Isolation: It acts as a massive filter that blocks "pollution" (pre-existing RF noise) coming from your building’s wall outlet, so you only measure the noise generated by your specific device.

Safe Signal Extraction: It safely couples the high-frequency interference from the power line to a 50Ω BNC port, allowing you to connect a sensitive spectrum analyser without risking high-voltage damage.

Compliance Alignment: Most emissions standards (CISPR 11/22, FCC Part 15) explicitly require a LISN for conducted emissions testing to ensure data is legally valid for CE or UKCA marking.

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Core Applications

Conducted Emissions Testing: Measuring the high-frequency "hash" generated by switching power supplies (SMPS) to ensure it doesn't exceed legal limits and interfere with other electronics.

Power Supply Characterisation: Helping R&D engineers see the raw noise profile of their DC-DC converters or AC-DC adapters during the design phase.

Filter Effectiveness Testing: Verifying how well an internal EMI filter is working by comparing noise levels with and without the filter engaged under a stable load.

Automotive & Aerospace Testing: Specialized LISNs are used to simulate the specific wiring harness impedances found in cars and aircraft for ISO and MIL-STD testing.

Category	Applications	Key Distinction	Stock Status	Price From
Automotive, Aerospace & Defence LISNsLow stock	For specialised DC systems and standards commonly used in automotive, aerospace and defence EMC testing, including CISPR 25, DO-160 and MIL-STD-461 applications.	Primarily specialist 5 µH / DC testing	In Stock	£252.00
DC & High-Current LISNs	For DC-powered equipment and power electronics, with options for higher-current and configurable single- or multi-line test setups.	Up to very high current ratings	On Backorder	£578.00
Single-Phase AC LISNsLow stock	For conducted emissions testing of single-phase mains-powered equipment, including commercial, laboratory and household electronic products.	Live & Neutral testing	In Stock	£578.00
Space & Satellite LISNsLow stock	For specialist spacecraft and satellite EMC testing, including low-inductance networks for ECSS-related supply-line test setups.	Specialist low-inductance networks	In Stock	£835.00
Specialist LISNs & ISNs	For less conventional EMC applications, including high-voltage or higher-frequency testing and balanced telecom/data lines.	VHF, high-voltage & telecom/data options	On Backorder	£807.00
Three-Phase AC LISNsLow stock	For conducted emissions testing of three-phase powered equipment, including higher-power industrial systems and machinery.	L1, L2, L3 & Neutral testing	In Stock	£578.00