Comprehensive Guide to EMI EMC Testing for Electrical and Electronic Devices.pdf

A crucial stage in the design and production of electrical devices is EMC/EMI testing lab. The FDA, FCC, and ISO, among other regulating organizations, have established strict limitations on the emissions that are permitted from electronic devices.

1. Comprehensive Guide to EMI/EMC Testing for Electrical and Electronic Devices


A crucial stage in the design and production of electrical devices is EMC/EMI testing lab. The FDA, FCC,
and ISO, among other regulating organizations, have established strict limitations on the emissions
that are permitted from electronic devices.
These EMC (electromagnetic compatibility) regulations ensure that electrical and electronic
equipment does not interfere with the operation of other equipment or fail to operate as intended as
a result of interference from other emissions, improving reliability and safety for anyone using such
equipment. EMC compliance testing failure can lead to penalties and product recalls.

What is EMI?
Electromagnetic interference (EMI), also known as Radio Frequency Interference (RFI), happens when
electromagnetic energy obstructs the functionality of an electronic device. Both man-made and
natural phenomena, such as electrical storms, solar radiation, or even cosmic sounds, can be the
source of EMI. Man-made sources include various electrical equipment like switch-mode power supply
and personal computers.
What is EMC?
The ability of a device to function as intended in a space with other electrical devices or sources of
EMI is known as electromagnetic compatibility (EMC). When a device does not adversely affect other
systems or devices by significantly altering the electromagnetic environment, it is said to be EMC-
compliant.
By limiting the unintentional generation, propagation, and reception of electromagnetic energy that
may cause undesirable effects like electromagnetic interference (EMI) or even physical damage in

2. operational equipment, electrical equipment and systems can function satisfactorily in their
electromagnetic environment.
EMI/EMC Testing is necessary for CE certification before these product manufacturers can export their
goods to European countries.
Various EMC test types
There are different EMC tests that testing labs run on electronics when they get them. EMC testing is
often split into two groups: immunity testing and emissions testing.
Immunity evaluation
Immunity testing analyses a product's response to both continuous and sporadic electromagnetic
energy exposure to determine its susceptibility to EMI. In order to test the device's power supply and
simulate a power surge, it is subjected to electromagnetic noise at various frequencies.
Radiated immunity testing evaluates a device's performance under conditions that simulate the
electromagnetic energy levels it will experience while operating.
Conducted immunity testing evaluates how the product will respond to electromagnetic energy from
another source unintentionally transmitted through a cable.
Emissions analysis
Assuring that any emissions from the device's internal electrical systems stay below the required
limits, emissions testing examines the amount of EMI generated by the tested product. Engineers can
measure the electromagnetic noise that their device generates precisely with the aid of antennas,
amplifiers, and spectrum analyzers.
Radiated emissions: This type of testing assesses a device's EMI production to see if it falls within the
predetermined ranges for its size and power. Conductive emissions testing measures the amount of
electromagnetic energy produced internally that could inadvertently travel along a cable and interfere
with other systems.