Self-certify EMC/EMI and device classifications - Page 1
Forum section: electronics / projects

author: FR4
author_rank: Newbie
timestamp: September 23, 2025, 09:15:42 am
content: Hello,I've been working on an electronics project for a while (building management, IoT, some RF, some sensing, etc) and have been given an opportunity to put it to use in the real world. In EU/UK.It's low volumes and I'm not selling anything, so I *could* get away without doing any EMI/EMC/CE/Radio Equipment Directive stuff, however this whole thing is too good of an opportunity to miss out on learning/gaining experience.My plan is to try to self-certify, as though I were going to see in low volumes, even though I'm not. I have access to standard test equipment (decent spectrum analyser) and can get access to some specific EMC/EMI equipment (Rigol/TekBox products) and generally know how to use it.My problem is finding a definitive answer to what tests I need to perform (ie what regulation/limits must be adhered to), and what goes in to the "design file" documentation etc. I know that this is the knowledge and experience you pay for in external testing, but I'd really like to do it myself. Is the only option to go through every standard and see if it applies, then read/understand them, or are there shortcuts? My backup plan is to find similar devices and see what they put in their declaration and copy them.Can anyone recommend any resources or books that might point me in the right direction?I am also aware that there are some checklists available for purchase - I'd be happy to pay if I could find good feedback on them, but I've found some public checklists and they were so generic they were basically useless and have put me off the paid versions.If anyone can recommend something like "practical EMC pre-compliance for dummies" or similar I'd be grateful.Thanks for any help!

author: AndyC_772
author_rank: Super Contributor
timestamp: September 23, 2025, 10:18:07 am
content: Especially if it's intentionally using RF, you really can't self-certify. You have no basis to claim the device is compliant unless you've actually tested it.If you're not "placing it on the market", you don't strictly have to claim compliance at all. If you are, then you'll need a trip to an EMC lab; they'll know the standards well and should be able to tell you what you must do in order to produce your technical file.

author: mtwieg
author_rank: Frequent Contributor
timestamp: September 23, 2025, 11:03:20 am
content: Sorry, if you're aiming for a CE mark then there's no substitute for testing by a notified body (TUV, Intertek, etc). Especially for EMC testing like radiated emissions and immunity."Pre-compliance" testing is sometimes referred to more informal testing you do to ensure you pass the "real" test. But you still would have to do the "real" test.The notified bodies are also in the business of consulting with clueless people who don't know what their obligations are. No harm in giving them a call, they've heard it all before.Quote from: AndyC_772 on September 23, 2025, 10:18:07 amBeen a while since I looked onto this, but I thought if you use, for example, a bluetooth module which is already FCC certified then that can save you a lot of hassle with testing. At lease that's how it is in the US, I'm assuming there's something equivalent to the FCC in the EU.

author: AndyC_772
author_rank: Super Contributor
timestamp: September 23, 2025, 11:43:22 am
content: TBH it's a while since I've looked into this too. From what I remember it certainly can save some testing if you can use a pre-approved module in exactly the pre-approved way - though you'd still have to document the way in which the module is used (positioning within the equipment, type of antenna, nearby ground planes etc).I wouldn't want to stand up in court and claim that 'yes, this intentional radio transmitter is definitely compliant, and I know this because I'm fairly sure I followed the data sheet properly'.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: September 23, 2025, 04:58:56 pm
content: You absolutely should be getting inCompliance magazine-https://incompliancemag.com/This stuff comes down to risk assessment. What's the downside if the unit turns out not to be compliant? Hazards, lawsuits, big product returns, jail time or confiscations? For low volume stuff and unintentional radiators, the risks are often minimal, and self-certification makes a lot of sense. If I were making something that could potentially crash airplanes or interfere with emergency services, I'd want the liability placed somewhere else as much as possible. You'll find the directives themselves are surprisingly non-specific. The supporting measurement standards are very specific but may not be appropriate to your product. They are not the only way, in spite of what the labs want you to believe. You may have to do some customization. The last few issues of inCompliance have focused on this.

author: tszaboo
author_rank: Super Contributor
timestamp: September 23, 2025, 05:07:06 pm
content: Quote from: mtwieg on September 23, 2025, 11:03:20 amQuote from: mtwieg on September 23, 2025, 11:03:20 amI have some experience dealing with notified bodies and certification agencies in the EU and the US.You really shouldn't make assumptions based on experience with just one, it's really different.