A line impedance stabilization network, also referred to as a LISN, is a device that provides quality RF impedance, stabilizes power lines, allows technicians to perform conducted emissions measurements, diverts unwanted signals from a power source, and more. They are vital for anyone working with signal analysis and performing conducted emissions testing.
What Is Conducted Emissions Testing?
Conducted emissions testing is used to monitor electromagnetic signals and find any irregularities in a device or system using RF signals. This type of testing can be used on electronic devices, power lines, and other electrical equipment. Without conducted emissions testing, operators run the risk of electromagnetic interference and other problems with a network. LISNs are used to carry out this crucial testing and provide important information to the technicians in charge of equipment repair or maintenance.
What is a LISN?
A LISN preserves the quality of EMC measurements and blocks RF noise from returning to the power mains. A LISN uses impedance and allows operators to meet a wide range of EMC test standards, including MIL-STDs, IEC/EN, FCC, CISPR, ISO, and RTCA DO-160. A complete list is below In order to analyze the equipment under test (EUT), LISNs connect to a power source and the EUT. The test is completed using RF impedance.
When connected to a power source, the LISN sends stable impedance of 50Ω to the EUT. This filters out the typical noise and fluctuations found in a power source and allows technicians to see if the EUT is responsible for any disturbances. It is also connected to a
spectrum analyzer which visualizes the test.
Applications
- Fan air cooling system
- RF noise port
- Spectrum analyzer or EMI receiver compatibility
- Large baseplate for optimal grounding
- Local and remote control
- RF shielding
- Artificial hand circuit (mimics human touch)
- Changeable pin-arrangements
- Insulated plugs for safer power connections
Note: Some of these applications depend on the model and specific equipment specs.
Test Standards
Line impedance stabilization is required for several EMC test standards, including those for vehicles, boats, airborne equipment, and radio frequency devices. ATEC's selection can cover all of these and more:
- MIL-STD 461G | Conducted Emissions
- RTCA DO-160 | Airborne Equipment
- EN 55022 | ITE Radio Disturbance Characteristics
- CISPR 16 | Radio Disturbance and Immunity
- CISPR 25 | Vehicles, Boats & Internal Combustion Engines
- FCC Part 15 | Radio Frequency Devices
- ISO 7637 | Road Vehicles: Electrical Disturbances from Conduction & Coupling
Choosing The Right LISN
ATEC offers customers affordable rental options for AC and DC LISNs from industry-leading manufacturers such as
PMM,
Com-Power, and
Solar Electronics. Finding the right equipment can be easy when you consider the test frequency, operating voltage, and type of current your test standard calls for. Reach out to an ATEC rental expert to learn more about our LISNs and other conducted emissions requirements and for help deciding on the right one.