EMI/EMC Testing Difference

The difference between EMC and EMI testing is that the former tests for immunity to electrical disturbances, while the latter determines whether or not a device will emit electromagnetic radiation.

1. EMI Vs EMC - What's the Difference

What is EMI?
EMI stands for "electromagnetic interference" while EMC stands for "electromagnetic compatibility."
Both terms refer to the way in which electrical and electronic devices interact with each other.
EMI is the disturbance that one device causes to another when they are operating at the same time.
This can happen when two devices are sharing the same power source, or when they are in close
proximity to each other. EMI can cause problems such as data loss, signal degradation, and even
equipment damage.
Uses of EMI
EMC is the ability of a device to function properly in the presence of other electrical and electronic
devices. It includes both immunity (the ability to resist interference) and emission (the ability to not
cause interference). Good EMC ensures that devices can operate together without causing problems.
So, in short, EMI is the interference that one device causes to another while EMC is the ability of a
device to function properly in the presence of other electrical and electronic devices.
Difference Between EMI & EMC
EMI and EMC are important considerations in the design of any electrical or electronic device. To
ensure good EMC, designers need to understand how interference can be generated and how it can
be minimized. They also need to understand the requirements of the various standards that apply to
their products.
There are two main types of standards for EMC:
product standards and immunity standards. Product standards define the maximum level of
interference that a device can emit without causing problems for other devices. Immunity standards
define the minimum level of immunity that a device must have to be considered immune to
interference.
Product standards are typically developed by voluntary organizations such as trade associations or
consortia. Immunity standards are usually developed by government agencies or international
organizations.

2. Product standards typically apply to specific types of devices, such as computers, televisions, and
radios. Immunity standards usually apply to specific environments, such as industrial sites or military
bases.
There are a number of different EMC standards that have been developed over the years. The most
important ones are listed below:
• FCC Part 15: This standard covers intentional and unintentional radiators. Intentional
radiators are devices that deliberately generate electromagnetic energy, such as radio
transmitters. Unintentional radiators are devices that generate electromagnetic energy as a
by-product of their normal operation, such as computers and electric motors.
• FCC Part 18: This standard covers the immunity of industrial, scientific, and medical (ISM)
equipment. ISM equipment is designed to be used in environments where there is a potential
for interference, such as factories and hospitals.
• MIL-STD 461: This standard covers the immunity of military equipment. It includes
requirements for both conducted and radiated emissions.
• EN 55022: This European standard covers the emission limits for information technology
equipment.
• EN 61000-3-2: This European standard covers the immunity requirements for household
appliances.
EMI/EMC testing are important considerations in the design of any electrical or electronic device. To
ensure good EMC, designers need to understand how interference can be generated and how it can
be minimized. They also need to understand the requirements of the various standards that apply to
their products.