First, you need to create a plan. A test plan is a requirement for most people working in defense. An EMI test plan is very helpful for communication between the customer, the test laboratory, and the design team. Even if it is not necessary, a test program is still a good idea. It forces you to deal with critical issues before they become major problems. This summary can be used as a checklist.
Identify the tests that are required. If you’re not sure which tests are required, contact your lab before your visit. There is nothing worse than not knowing what you need to do. The test configuration should be determined for each test. This is usually emi testing lab done in the test specification.
Define failure criteria. This is simple with emissions. Is the level above or below the limit? But with immunity/susceptibility, however, you may need to define failures. Is it acceptable to reset the sensor with recovery? What level of perturbation can an analog sensor withstand?
The failure criteria will vary depending on the equipment being tested. Sometimes you can be more flexible. You can start by looking at the European Union EMI specifications. This information should be included in your plan. Also, make sure you get agreement ahead of time on the failure criteria.
Locate failure monitors. This is also easy with emissions – just look at the spectrum analyzer. Immunity/susceptibility are not as easy. How do you know when something is a failure? Are you using special software? Special software? Or hardware like a blinking heartbeat detector? You could also use a video camera to show indicators on the EUT (equipment currently under test).
Determine the hardware of your equipment. Which equipment are you going to test? Do you need peripherals? How about memory and I/O configurations. It is best to test a “worst-case” configuration. This assumes that less configurations will have fewer EMI problems.
Determine the software you need. Do you require special software or test software? Some software might even be required. The prescribed emissions test software includes reading/writing to hard drives, peripherals, and a “scrollingH” test pattern for monitors. It is unfair to leave the system inactive. You must exercise the hardware.
For immunity/susceptibility, how will you monitor, recognize, and report failures? Is the standard software sufficient? Or do you require special software? Is that software compatible with the EUT or remote equipment? Select the support hardware. Are you looking for passive peripherals or active exercisers Do you have to create special hardware and software? Do you need special power or cooling?
Cables and connectors are important. Make sure shielded cables are properly terminated. How will cables penetrate the chamber? This may require you to create a test fixture. Cables are prone to problems. Before you go to the lab, make sure they are checked. One engineer still remembers telling his colleague, “I thought you brought the good cables.”
Make sure you have a complete tool kit with spares. You should have spare boards. You can even bring an additional system. It is not good to lose your equipment during tests. Backup software is also recommended. It is also a good idea to include spare parts such as ferrites, small caps and EMI copper tape. If you have any minor modifications to your board, a soldering station is a good option. While most of this information is available in the lab, it’s better to have it on hand.