The Requirement

Electromagnetic Compatibility (EMC) requires a device, equipment or system to function properly in its operating environment without introducing intolerable Electro- magnetic Interference (EMI) to the surroundings. EMC comprises the control of unintentional emissions from a range of products that can interfere with radio communications, as well as protection from a range of devices susceptible to the intentional transmission. Two aspects that must be considered during development, maintenance and operations are emission and immunity.

Under an EMC validation project for MTR Phase IV Light Rail Vehicles (LRVs), BMT's role was to obtain electromagnetic field emission measurement data and verify that the LRVs' emission levels meet the EMC standard: EN 50121 Part 3-1: Rolling Stock – Train and Complete Vehicle.

Our Approach

The methods of measurements were based on the EMC standards: EN50121-3-1 and EN50121-2. The measurements were divided into two parts (Part 1: Stationary Mode; and Part 2: Slow Moving Mode).

Both parts were conducted using the same Loop Antenna, Bilog Antenna, and EMI Test Receiver to pick up the signal level of Medium Frequency (MF) and Very High Frequency (VHF) ranges generated by the LRVs. The ambient noise before and after each part of measurement of these vehicles under testing was also measured.

Outcomes and Benefits

BMT’s experienced team provided the following deliverables to the client:

• Solution to site constraints for electric field measurements;
• Test plans detailing the test setup and defining the equipment under test (EUT);
• Measurement raw data that was obtained from the physical on-site testing;
• A test report to compare and contrast the measurement data and draw conclusions of the test results.