SparkFun Forums

[az1324]

I was watching the SFU Sell Your Widget video and noticed in the part about FCC for Unintentional Radiators Nate basically said throw a sticker on it and sell it. (This is in keeping with the video's theme of don't worry about problems until you are staring them in the eye.) He also mentioned some kind of test equipment for a basic RF power emissions measurement. But that sticker implies that you have a declaration of conformity on file and ready if the FCC ever requests it. And in that declaration should be formal test results from an FCC certified testing facility. From what I understand the chances that the FCC will ever request that document are very slim unless your device is pulling a White Noise and Michael Keaton is around or something. But if they do and you don't have the required proof, the possible fines are enough to easily bankrupt a small company. Will you be fined if your device actually IS compliant with the rules, you just don't have the DoC?? I don't know. And what are the chances that your device will be leaking some RF just above the limit? If you do not have enough experience to be sure your device is compliant, seems a little risky.

So... why not just test? Well for whatever reason (probably because it is a racket) testing is quite expensive. And the problem is it seems like there is nothing in place for small inexpensive devices. You will use the same test chambers and pay the same rates as for larger more expensive devices. (Correct me if I am wrong.) And if you don't pass on the first try and can't fix the problem on the spot you are in for at least one more test fee: $1500-$2500 per test in the US? This is potentially more than your first production run cost and you don't even know if the product is successful yet. I have heard you can do offshore testing in China or elsewhere for $300-$500 but obviously you can't try to fix problems on the spot. So where is the BatchFCC test? Maybe if you have a bunch of similar small products you could test them all in one session and split the fees?

Anyone else with experience or advice on this please post.

[az1324]

So... nothing on offshore testing, batch testing strategies, or willful disobedience?

[markaren1]

locate an ex-employee of a test house

buy them a beer

listen, with ears wide open...

-mark

[rmteo1]

You may want to check FCC Part 15, in particular Subpart B - Unintentional Radiators. For example, there is this:

Section 15.103 Exempted devices.

The following devices are subject only to the general conditions of operation in Sections 15.5 and
15.29 and are exempt from the specific technical standards and other requirements contained in this Part.
The operator of the exempted device shall be required to stop operating the device upon a finding by the
Commission or its representative that the device is causing harmful interference. Operation shall not
resume until the condition causing the harmful interference has been corrected. Although not mandatory,
it is strongly recommended that the manufacturer of an exempted device endeavor to have the device
meet the specific technical standards in this Part.
(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles
and aircraft.
(b) A digital device used exclusively as an electronic control or power system utilized by a
public utility or in an industrial plant. The term public utility includes equipment only to the extent that it
is in a dedicated building or large room owned or leased by the utility and does not extend to equipment
installed in a subscriber's facility.
(c) A digital device used exclusively as industrial, commercial, or medical test equipment.
(d) A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher,
clothes dryer, air conditioner (central or window), etc.
(e) Specialized medical digital devices (generally used at the direction of or under the
supervision of a licensed health care practitioner) whether used in a patient's home or a health care
facility. Non-specialized medical devices, i.e., devices marketed through retail channels for use by the
general public, are not exempted. This exemption also does not apply to digital devices used for record
keeping or any purpose not directly connected with medical treatment.
(f) Digital devices that have a power consumption not exceeding 6 nW.
(g) Joystick controllers or similar devices, such as a mouse, used with digital devices but which
contain only non-digital circuitry or a simple circuit to convert the signal to the format required (e.g., an
integrated circuit for analog to digital conversion) are viewed as passive add-on devices, not themselves
directly subject to the technical standards or the equipment authorization requirements.
(h) Digital devices in which both the highest frequency generated and the highest frequency used
are less than 1.705 MHz and which do not operate from the AC power lines or contain provisions for
operation while connected to the AC power lines. Digital devices that include, or make provision for the
use of, battery eliminators, AC adaptors or battery chargers which permit operation while charging or that
connect to the AC power lines indirectly, obtaining their power through another device which is
connected to the AC power lines, do not fall under this exemption.
(i) Responsible parties should note that equipment containing more than one device is not
exempt from the technical standards in this Part unless all of the devices in the equipment meet the
criteria for exemption. If only one of the included devices qualifies for exemption, the remainder of the
equipment must comply with any applicable regulations. If a device performs more than one function and
all of those functions do not meet the criteria for exemption, the device does not qualify for inclusion
under the exemptions.

[az1324]

Yes I know about the exemptions and that the test equipment one is widely used. Unfortunately that is not going to help me. Just seems strange that no one really talks about it. What is it, fight club? And should I really be able to get an MRI cheaper than a radiated and conducted emissions test?

Some devices that definitely have a high-speed mcu inside do not have any FCC or other markings on the device or in the manual. Some have ETL listings for UL and CSA standards but no FCC mentions. Does ETL listing imply FCC tested? Others have all kinds of certifications. For example, I don't own this device but it does not appear to have any FCC markings on the device or in the manual: http://elkproducts.com/products/elk-ip232.htm. It's not marketed as test equipment.

[Blackfin]

My experience with regulatory affairs goes back 15+ years though is largely limited to medical products. In that arena we really didn't screw around and went "by the book." A typical product might have seen electrical safety at UL to IEC60601-1 with national deviations for Canada (CAN/CSA C22.2 No.601), US (UL60601-1), Europe (EN60601-1) etc plus EMC to IEC60601-1-2, emissions to CISPR11/EN55011 and FCC Pt 18 Class B etc etc ad nauseum.

Fundamentally speaking, if you market a device that has a clock and is not otherwise exempted you are required to ensure that the device does not exceed the emissions limits set out by the FCC for that type of device. I would be wary of applying a sticker to a device stating compliance when no testing has been performed. Some devices may indeed be empirically expected to perform well under the FCC radar, so to speak, and are "givens" when it comes to compliance. I can see an internally clocked PIC running at 4MHz on a small PCB simply flashing an LED as being a gimme (though it definitely possible to make that noisy too...) but anything more complex and it's a roll of the dice to declare compliance when you haven't tested.

One thing that may help demonstrate at least a bit of due diligence is the "engineering scan." You arrange with a test facility for an hour or so in an OATS (open-field test site) or semi-anechoic chamber at least 10m in size and ask them to do an engineering scan from, say, 30MHz to 1GHz for FCC Class B limits in both vertical and horizontal antenna polarizations using a peak detector. Such a scan is like skimming a book...they'll just do an overall scan of your device as it operates on a table on a rotary platform in the chamber and look for peaks in excess of the limits. They may not zoom in on any peaks (e.g. those that are over the limit or those that are close to the limit) and probably won't offer any debugging or diagnostic help but they should be able to provide you with a plot or file showing the high-level performance of you device. If you're confident that the device is good to go you can file these results in your technical file and use it as proof of at least some semblance of due-diligence in the future should someone from the FCC come knocking. Engineering scans are helpful during development to keep tabs on whether a design is keeping pace with the limits as it evolves. The lab I used in the past changed $500/hr for an OATS-qualified 10m chamber though they charged less for a non-OATS chamber. They might charge less for a true OATS scan... Anyway, it's cheaper than getting a full report done and filed and at least demonstrates that you did something to ensure compliance before selling broadly.

You may also be required to follow the FCCs markings rules to the device or accompanying documents with the familiar "This device complies with part 15 of the FCC Rules..." statement.

But the FCC is federal and of late, from what I gather, isn't playing very nicely with those that market un-tested, un-approved devices. As can be seen on page 4 of this PDF:

http://www.wll.com/newsletter/T&EIssue22.pdf

their options for enforcement include the seizure of equipment, fines, and possibly even jail for “knowing violations” of law. There are numerous instances of the FCC coming down pretty hard on outfits selling questionable product. Your business plan should definitely include a risk assessment for not obtaining FCC testing and saving $$$ up front weighed against paying now and not having to worry at all about future problems with that federal agency.

[leon_heller]

Where I used to work they save a lot of money by hiring the test facility for a half-day and doing their own initial testing for CE requirements (more stringent than FCC). Any problems are then fixed and the proper testing is a formality. I designed their first product, it only failed the initial tests because an RS-232 lead was radiating a harmonic of one of the oscillators at VHF. Adding some filters to the connector cured the problem and it then passed the formal tests.

[Blackfin]

Where I used to work they save a lot of money by hiring the test facility for a half-day and doing their own initial testing for CE requirements (more stringent than FCC). Any problems are then fixed and the proper testing is a formality. I designed their first product, it only failed the initial tests because an RS-232 lead was radiating a harmonic of one of the oscillators at VHF. Adding some filters to the connector cured the problem and it then passed the formal tests.

This is pretty common practice. As I mentioned earlier, most design houses will utilize engineering scans during development, especially of more complex designs. A PIC at 4MHz is one thing...an ARM9 running 200MHz with 100MHz clocking external SDRAM is quite another. It certainly makes sense to use best practices in the initial design of the product and verify during development with short, efficient engineering scans at critical points. The fewer surprises one gets at "finals" the better.

There are still questions related to the OP: (a) Does one do anything? (b) Does one bother to do the qualification scans to get a feeling for how their product is doing and (c) Does one proceed to the final test and report generation?

By not doing anything one saves money up front at the risk of pissing the FCC off later and possibly facing a confrontation with a federal authority that has been shown to be getting more belligerent and less tolerant over the last few years.

Qualification/engineering scans make good business sense to me, especially for more complex designs. But for an individual guy working out of his garage inventing the next Apple, even a few hundred dollars for an hour's chamber time is seen as an extravagance. If he has no intention of doing the final testing and reporting (i.e. he's weighed the legal and financial hazards and judges the risk of the no-test route acceptable) then the scan would at least be useful to know roughly where he and his product stands and would help determine risk. Indeed, it may even serve to bolster his risk analysis conclusion (i.e. "the pre-scan showed nothing of concern so the 'formality' of a final test isn't needed".) Without a pre-scan he's basically in the "not doing anything" category above and is taking on a certain degree of risk without knowing all the facts.

The final test and report is the risk-free way to go though it carries immediate cost penalties. For a cash-strapped start-up it may not be feasible to eat that expense. Perhaps the individual says to himself "Let me get some pre-scans to satisfy me in the short term and after selling a hundred widgets I'll have enough to go to the lab and finalize the reporting to dot the 'i's and cross the 't's, so to speak."

If you're making a new doo-dad to measure the altitude a model rocket achieves and will be selling only a hundred or two to a very limited, niche-y group or rocketnerds, you're probably good to go with no testing. If you're planning on going commercial and selling quantities openly over the web or through distributors to the general public then find the funds and do the testing...

[esklar81]

Blackfin,
I agree with your analysis in general and I think you've made the key points well. EMC isn't my specialty, but I've been a product safety engineer for most of the last couple of decades and do have some familiarity with the requirements.

On a specific point:

If you're making a new doo-dad to measure the altitude a model rocket achieves and will be selling only a hundred or two to a very limited, niche-y group or rocketnerds, you're probably good to go with no testing. If you're planning on going commercial and selling quantities openly over the web or through distributors to the general public then find the funds and do the testing...

Wouldn't a rocket altimeter be exempted by:
(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.
?
Eric

[Blackfin]

Wouldn't a rocket altimeter be exempted by:
(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.?

I don't know if saying that a model rocket constitutes a "transportation vehicle" would wash with the FCC but you never know.

Perhaps picking an example where some confusion or interpretation might be possible wasn't a good idea. I meant to convey that if you're target audience is very tight and focused and unlikely to run into or cause trouble with the FCC you could probably fly under the radar without garnering much attention, sort of like how selling home baked goods at a flea market stand probably won't net you the attention of the IRS or local food-health regulatory authorities... (then again for food it just might...)

If you're going for a widespread consumer market and want to distribute through Walmart to a wide range and large number of people, the risk goes up of being "caught". This is especially true if you have competition: If they went to the trouble of FCCing their stuff and you didn't and they get wind of it they may squeal on you just in the spirit of competition and marketshare.

[esklar81]

Blackfin,
I didn't find anything useful in 47CFR indicating whether a model rocket would be considered a "transportation vehicle". I did, however, come across:

47 CFR 15.23 Home-built devices.
(a) Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use.
(b) It is recognized that the individual builder of home-built equipment may not possess the means to perform the measurements for determining compliance with the regulations. In this case, the builder is expected to employ good engineering practices to meet the specified technical standards to the greatest extent practicable. The provisions of §15.5 apply to this equipment.

available at:
http://ecfr.gpoaccess.gov/cgi/t/text/te ... 1.0.1.1.14
and thought I should post it as a reminder that none of this issue pertains until one is looking to offer a device for sale.
Eric

[Blackfin]

Blackfin,
I didn't find anything useful in 47CFR indicating whether a model rocket would be considered a "transportation vehicle". I did, however, come across ... 47 CFR 15.23 Home-built devices.

Right, but since the original poster started this thread with "I was watching the SFU Sell Your Widget video..." the idea of purely homebuilt devices doesn't apply although it's good information for those lurking that might be thinking their homebrew gadgets might be of interest to the FCC.

FWIW, and not that it matters really, I had a quick look around and found one model rocket telemetry system that claims to be FCC-compliant and which is offered with a CE-mark if needed:

http://www.eagletreesystems.com/Support ... rocket.pdf

[az1324]

Thanks for the replies. Good to get some discussion on the matter.

The preference is obviously to be tested in some form, while minimizing the expense. The pretest or engineering test seems like a very attractive option. A few hundred dollars is not a big deal. When the costs start getting up to the several thousand dollars level it seems a bit harder to swallow. Is there some reason the plots from this test would not be sufficient for assembling ones own DoC? There doesn't seem to be much to it. http://www.adiengineering.com/products/ ... Report.pdf Does the DoC itself have to come from the lab in finished form?

I have several small devices, which are very similar, in development. It seems like the most sensible thing to do would be to test them all at once, thus distributing the expense. However this means completing them all first and delaying any income from sales until they can all be built and tested.

Though these products are fairly niche gadgets, I would like to eventually pursue as wide a distribution as possible. Tipoffs from competition could be a concern also, as I plan to undercut the market... another reason to keep costs as low as possible.

Questions remaining:

Does an ETL listing imply FCC certified? If not, then various competing products have none.

What is the best way to find a lab with the best rates? It seems like none of them publish their rates on the web.

Anyone have experience with offshore testing?

[Blackfin]

Questions remaining:

Does an ETL listing imply FCC certified? If not, then various competing products have none.

Not necessarily. A place like UL or Intertek (or like NRTL) will general focus on product safety. For example, for a product like a computer accessory, they'd probably test to IEC/EN/UL60950-1 and generate a report stating that the product is safe. They may offer a service where they will take care of obtaining FCC on the device as well and would sub-contract that out if they lacked the facilities to do the testing themselves. The expense of having them act as middle man can be quite high.

The lack of any FCC statements on the competing devices or in their accompanying documents would probably mean they don't have any FCC testing done.

What is the best way to find a lab with the best rates? It seems like none of them publish their rates on the web.

Send them a RFQ (request for quotation.)

Anyone have experience with offshore testing?

Sorry, not I. All of the testing I've been involved with was done in North America.

[dbvanhorn]

Dennis King at EMI testlabs in Longmont will do part 15 radiated and conducted scans pretty reasonably, and he is a much better resource than most labs in that he can work with you to figure out where your issues live (if any) and what to do about them.

I've been working with him for about four years now, never had a bad experience. He's the best resource in this direction I've ever come across.

Similarly for antenna matching issues, Don DeGroot at CCNI also in Longmont is a great resource. Matching your transmitter to the antenna can be critical not only for range optimization, but also for reduction of transmitter harmonics caused by the impedance mismatch and power reflected back into the transmitter.