EMC compliance testing

S

Scott Miller

Guest
I'm working on a product that will apparently need FCC Class B certification
in the US, and the equivalent CE Marking in Europe. Can anyone suggest a
good, low-cost lab for the testing? Like under $2500?

Does anyone do cheaper 'pre-testing' so that I might gauge how close I am to
compliance? I really don't have the equipment I need in-house to do that
sort of testing.

Thanks,

Scott
 
Scott Miller wrote:

I'm working on a product that will apparently need FCC Class B certification
in the US, and the equivalent CE Marking in Europe. Can anyone suggest a
good, low-cost lab for the testing? Like under $2500?
Click to expand...
Not in the US. Don't forget that you also need to meet the Low Voltage Directive
( safety ) too to apply the CE mark.


Does anyone do cheaper 'pre-testing' so that I might gauge how close I am to
compliance? I really don't have the equipment I need in-house to do that
sort of testing.
Click to expand...
Pre-compliance testing is a good idea, especially if you're new to it all. I
chanced up on a semi-retired emc expert who we use from time to time. Last time,
I think he charged about Ł300/day and brought the necessary equipment to us.
You'll need to find a suitable location for certain tests too that's 'rf benign'
e.g. has no steel in the construction of the building and isn't near anything
like that. We used a hut in a playing field.


Graham
 
http://www.geocities.com/leon_heller
"Scott Miller" <scott@3xf.com> wrote in message
news:11593l47s49ht0a@corp.supernews.com...
I'm working on a product that will apparently need FCC Class B
certification in the US, and the equivalent CE Marking in Europe. Can
anyone suggest a good, low-cost lab for the testing? Like under $2500?

Does anyone do cheaper 'pre-testing' so that I might gauge how close I am
to compliance? I really don't have the equipment I need in-house to do
that sort of testing.
Click to expand...
Where I used to work they book a test facility for half a day for
preliminary testing. It isn't expensive. That usually shows up one or two
problems with emissions which are easily fixed and the equipment generally
passes fist time after that.

Leon
--
Leon Heller, G1HSM
 
Not in the US. Don't forget that you also need to meet the Low Voltage
Directive
( safety ) too to apply the CE mark.
Click to expand...
The device will be powered by USB or a 9-volt wall wart. It's my
understanding that it doesn't need Low Voltage Directive compliance if it's
under 75 VDC and the external power supply is itself approved. Is that
right?

Pre-compliance testing is a good idea, especially if you're new to it all.
I
chanced up on a semi-retired emc expert who we use from time to time. Last
time,
I think he charged about Ł300/day and brought the necessary equipment to
us.
You'll need to find a suitable location for certain tests too that's 'rf
benign'
e.g. has no steel in the construction of the building and isn't near
anything
like that. We used a hut in a playing field.
Click to expand...
Anyone know where I can find someone like this in California? I'm new to
this and it'd be nice to have some hand-holding. And if it's someone
willing to give a break to a very small startup company, that'd be even
better.

Scott
 
Where I used to work they book a test facility for half a day for
preliminary testing. It isn't expensive. That usually shows up one or two
problems with emissions which are easily fixed and the equipment generally
passes fist time after that.
Click to expand...
And would the company provide their own engineers for the testing, or does
that come with the facility? I'd like to talk to someone who's been through
the whole testing cycle - there's a lot I don't understand about the test
setup, especially when it comes to adding cables and connecting the device
under test to other devices.

Scott
 
"Scott Miller" <scott@3xf.com> wrote in message
news:115atjpkil5t7c2@corp.supernews.com...
Not in the US. Don't forget that you also need to meet the Low Voltage
Directive
( safety ) too to apply the CE mark.

The device will be powered by USB or a 9-volt wall wart. It's my
understanding that it doesn't need Low Voltage Directive compliance if
it's
under 75 VDC and the external power supply is itself approved. Is that
right?

Everything needs consideration to the LVD.
Click to expand...
Just because the supply to your equipment is SELV (not 75V by the way) it
does not mean that your equipment is 'safe'.
A simple example is the camping fluo lamp. This works off a 12V car battery
but powers a fluorescent tube that is often cold cathode struck and requires
an output of several hundred volts.

However if you are confident (and expert) enough to verify that the
equipment will not 'step up' the incoming SELV , or the user will have no
access to a voltage above SELV, then just declare it as such.
 
Scott Miller wrote:

Where I used to work they book a test facility for half a day for
preliminary testing. It isn't expensive. That usually shows up one or two
problems with emissions which are easily fixed and the equipment generally
passes fist time after that.


And would the company provide their own engineers for the testing, or does
that come with the facility? I'd like to talk to someone who's been through
the whole testing cycle - there's a lot I don't understand about the test
setup, especially when it comes to adding cables and connecting the device
under test to other devices.
Click to expand...

After telling us the corner specifications, we could
introduce you to the required tests.

Is the device for industrial / household / medical applications ?
Is it powered from the powerline / batteries / external power supply ?
Is it connected to other stuff ? By what connection ? Serial ?
What is the highest internal voltage ? < 48V ? > 48V ? line ?


Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net
 
Scott Miller wrote:

Not in the US. Don't forget that you also need to meet the Low Voltage
Directive
( safety ) too to apply the CE mark.

The device will be powered by USB or a 9-volt wall wart. It's my
understanding that it doesn't need Low Voltage Directive compliance if it's
under 75 VDC and the external power supply is itself approved. Is that
right?
Click to expand...
Ahhh - OK - then no need for LVD.


Pre-compliance testing is a good idea, especially if you're new to it all.
I
chanced up on a semi-retired emc expert who we use from time to time. Last
time,
I think he charged about Ł300/day and brought the necessary equipment to
us.
You'll need to find a suitable location for certain tests too that's 'rf
benign'
e.g. has no steel in the construction of the building and isn't near
anything
like that. We used a hut in a playing field.

Anyone know where I can find someone like this in California? I'm new to
this and it'd be nice to have some hand-holding. And if it's someone
willing to give a break to a very small startup company, that'd be even
better.
Click to expand...
If you're new to it, the hand holding is invaluable. I've used that consultant I
mentioned since ooohhh 1987 and I've leant many of the tricks of the trade from
him.

Good luck looking. I just asked around and got lucky.


Graham
 
After telling us the corner specifications, we could
introduce you to the required tests.

Is the device for industrial / household / medical applications ?
Is it powered from the powerline / batteries / external power supply ?
Is it connected to other stuff ? By what connection ? Serial ?
What is the highest internal voltage ? < 48V ? > 48V ? line ?
Click to expand...
Household. There would certainly be some commercial/industrial usage, but
more often hobbyists in a home environment.

Power will be supplied through USB connection (5 volts) or external supply
for standalone operation - generally an off-the-shelf 9v wall wart I expect.
Maximum input voltage would be maybe 14 volts. The majority of the
internals will run at 3 volts. Haven't chosen a regulator yet, but it won't
be anything elaborate. No plans for internal batteries at this point.

It could connect to a PC through USB or RS-232, GPS receiver through RS-232,
and VHF or UHF radios through an audio cable. It's got an SD/MMC flash card
slot for removable storage.

Thanks,

Scott
 
Scott Miller wrote:
After telling us the corner specifications, we could
introduce you to the required tests.

Is the device for industrial / household / medical applications ?
Is it powered from the powerline / batteries / external power supply ?
Is it connected to other stuff ? By what connection ? Serial ?
What is the highest internal voltage ? < 48V ? > 48V ? line ?


Household. There would certainly be some commercial/industrial usage, but
more often hobbyists in a home environment.

Power will be supplied through USB connection (5 volts) or external supply
for standalone operation - generally an off-the-shelf 9v wall wart I expect.
Maximum input voltage would be maybe 14 volts. The majority of the
internals will run at 3 volts. Haven't chosen a regulator yet, but it won't
be anything elaborate. No plans for internal batteries at this point.

It could connect to a PC through USB or RS-232, GPS receiver through RS-232,
and VHF or UHF radios through an audio cable. It's got an SD/MMC flash card
slot for removable storage.
Click to expand...
By only using low voltage to be supplied from external,
you already offloaded the power line spike tests.
Next then is radiated and conducted emission as well as
radiated and conducted susceptibility to RF from DC to
3GHz. There, your working device with its standard
connectionsis subject to
1) radiation in the mentioned frequency range on cable
or through the antenna. The device has to keep on
working.
2) the radiation of your device on cable as well as on
cable is measured and some values not to be exceeded.

Power and signal lines can be made to conform by shorting
the RF to the case with 100nF caps for DC and smaller ones
depending on the signal frequency. Oops, household cases
are usually not from metal.

Industrial metal cases have to be earthed.

Household cases are usually from plastic, this is somewhat
harder to shield.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net
 
I recently used UL for just the FCC Class B and paid about that amount,
which was the lowest fee I have ever paid for this testing. I think UL just
added this service recently. Up to now we used independent labs.
Jeff

"Scott Miller" <scott@3xf.com> wrote in message
news:11593l47s49ht0a@corp.supernews.com...
I'm working on a product that will apparently need FCC Class B
certification in the US, and the equivalent CE Marking in Europe. Can
anyone suggest a good, low-cost lab for the testing? Like under $2500?

Does anyone do cheaper 'pre-testing' so that I might gauge how close I am
to compliance? I really don't have the equipment I need in-house to do
that sort of testing.

Thanks,

Scott
Click to expand...
 
Power and signal lines can be made to conform by shorting
the RF to the case with 100nF caps for DC and smaller ones
depending on the signal frequency. Oops, household cases
are usually not from metal.
Click to expand...
This will be a metal case - either steel or aluminum, still working with the
enclosure vendor on that. It'll add a few dollars to the price compared to
a plastic case, but I think it'll be worth it. Aside from the shielding,
there's marketing value in providing a sturdy, durable enclosure. Too many
products these days are cheap and fragile.

Industrial metal cases have to be earthed.
Click to expand...
I saw some mention of having a ground (earth) connection to the case through
a screw that serves no other purpose - i.e., not a screw that holds the case
on. I don't remember who's requirement that was - might have been a UL
thing, and I'm not sure if it's applicable.

I will certainly have plenty of decoupling on the power and signal lines. I
hadn't given any thought yet to the electrical connection with the case. I
suppose it'll just have the ground plane exposed around the screw holes.
I'll ask my PCB and enclosure vendors how they usually set that up.

Thanks...

Scott
 
Someone was just telling me that UL was outrageously expensive, but maybe
that was for their usual safety testing. I suppose they try to sell you
their other services as well?

Scott

"Jeff" <koebrich@sbcglobal.net> wrote in message
news:OTt5e.16476$ZB6.4482@newssvr19.news.prodigy.com...
I recently used UL for just the FCC Class B and paid about that amount,
which was the lowest fee I have ever paid for this testing. I think UL
just added this service recently. Up to now we used independent labs.
Jeff

"Scott Miller" <scott@3xf.com> wrote in message
news:11593l47s49ht0a@corp.supernews.com...
I'm working on a product that will apparently need FCC Class B
certification in the US, and the equivalent CE Marking in Europe. Can
anyone suggest a good, low-cost lab for the testing? Like under $2500?

Does anyone do cheaper 'pre-testing' so that I might gauge how close I am
to compliance? I really don't have the equipment I need in-house to do
that sort of testing.

Thanks,

Scott
Click to expand...
 
Scott Miller wrote:

Someone was just telling me that UL was outrageously expensive, but maybe
that was for their usual safety testing. I suppose they try to sell you
their other services as well?
Click to expand...
Undoubtedly !

The last lab I used for conformity testing was ETL Semko in the UK. They weren't
too bad on price but hopeless as regards understanding the cable connections for
a practical test. That's especially difficult with a product like an audio mixer
as I was submitting, where you can have so many possibilities - you just have to
make a sensible compromise between minimal and absurdly out of the world
possibilities.

I notice they are represented in the USA too.

http://www.usa.intertek-etlsemko.com/

Worth a call I reckon. Explain that you need FCC and CE at the same time and
there should be minimal extra cost. They just need to run some tests with
slightly different limits. CE requires immunity though - which I believe FCC
still doesn't ( not sure it can require so, given it's role in the regulatory
structure - but pls correct me if I'm mistaken ).


Graham
 
I notice they are represented in the USA too.

http://www.usa.intertek-etlsemko.com/
Click to expand...
I'll check them out.

slightly different limits. CE requires immunity though - which I believe
FCC
still doesn't ( not sure it can require so, given it's role in the
regulatory
structure - but pls correct me if I'm mistaken ).
Click to expand...
I think you're right. Part 15 doesn't specify any immunity requirements,
though it does say something about the device having to accept any
interference caused by other devices.

Thanks,

Scott
 
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