RFI/EMI Testers are used to monitor the presence of undesirable electromagnetic interference (EMI) and radio frequency interference (RFI) in an electrical equipment. EMI and RFI are electromagnetic emissions ejected by electrical circuits. They are a sort of disturbance that may be man-made or natural, and which causes an undesirable response or degradation in the performance of an electrical equipment.

EMI/RFI testers identify interference that could potentially cause a failure, which might interfere with medical equipment or halt a manufacturing process.

Working of EMI/RFI Testers

• These testers employ different methods to test interference.
• RFI/EMI testers uses a line impedance stabilization network (LISN) that is connected in continuity with the power lines to the equipment.
• The passive LISN networks establish a consistent blockage to ensure repeatability of test results.
• Conducted emissions are measured by using an RF connection to a port on the LISN.
• Radiated emissions are measured using an antenna or current-detecting probe.
• An EMI tester has four operational methods: horizontal high band, horizontal low band, vertical high band and vertical low band.
• Common sources of conducted interference include switching power supplies, AC motors, and microprocessors.

Applications of RFI/EMI Testers

• Military Equipments
• Medical Equipments
• Electrical Devices
• Electronic Devices