Hi, Everyone.
When we were qualifying burglar alarm motion detectors, we required the ESD
test to be performed, even though in normal operation no one would touch the
devices. However, we adjusted the pass/fail criteria such that an ESD event
causing a momentary alarm signal would not fail the
Agree with Don. May not be necessary but maintenance type ESD testing is a
very good idea. In fact part of the NEBS (Telecommunications test suite) has
circuit card ESD tests specifically for maintenance and production handling.
They do have a product ESD test but they are in different documents.
Thats true Mike - but the lab is verifying the
performance to a standard. If the standard says
no test - then no test. One can of course
have a special test for the company.
Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel: 303-706-5467
Fax:
Don,
ESD mitigation instructions are typically included with board products
intended for installation in a PC. The board is shipped in an ESD bag
with a warning label sealing it. Thus, the board is not expected to
survive higher ESD levels - the user/installer is expected to protect
it. Once
Jan, first off this list is for safety (PSTC), EMC and other regulatory
issues, so asking such a questions is fine.
At least in the USA the air above the ceiling tiles can be an air return
plenum for the heating and air-conditioning systems. Anything burning in the
air return plenum will
If installation is normal usage, then should all those bare boards
installed in PCs should be tested for ESD resistance in their bare state?
Or is the distinction between a product and a component that goes into a
product (though some may argue that, for example, a modem board is a
I think this raises the difference between what's really required BY LAW and
what is good engineering practice, or QUALITY. Although I personally am always
for high quality and therefore perform tests above and beyond whenever I can,
there are numerous instances where this is not prudent.
I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote
(in 42050df556283a4d977b111eb7063208139...@orsmsx407.jf.intel.com)
about 'ESD - not applicable ?' on Mon, 23 Jun 2003:
Did the lab explain how the equipment would be installed, if not
touched by human hands?
By
I submit my opinion humbly in the light of the group's massive collective
knowledge (grovel, grovel).
I disagree with your lab. Your customers may not NEED to touch your product;
but they COULD touch it. To me, that is accessible. Why? Because its
outer surface could be touched by a number
And installation is normal usage. Now, it would be interesting to know just
what type of product we’re talking about.
Ghery Pettit
Intel Corporation
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Monday, June 23, 2003 1:05 PM
To: emc-p...@majordomo.ieee.org
That's what I thought. The same approach must be used whether measuring
site attenuation or measuring RE from the test sample, right? I don't
understand how it could work otherwise.
From: brent.dew...@us.datex-ohmeda.com
Reply-To: brent.dew...@us.datex-ohmeda.com
Date: Mon, 23 Jun 2003
Clause 8.3.1 of EN 61000-4-2 says The static electricity discharges shall be
applied only to such points and surfaces of the EUT which are acessible to
personnel during normal usage. And it also says The application of
discharges to any point of the equipment which is assessible only for
Tim Pierce wrote
I have worked with sites that used the hardware cloth (screen) over
concrete
in the past. When the tears would happen, they would patch that area ...
Tim,
If this were a reflector antenna, holes in the reflector would be kept to
0.1 wavelength at the highest frequency. This
I think the local test lab is correct, since the product will be accessed
only for installation or maintenance. This is similar to the situation
where the covers are off a device for servicing - ESD testing is not
required for the internal circuitry of a device with the covers off.
Having
Hi Ken,
Only the maximum reading over the scan height is used. The received signal
is nominally the vector sum of the line of sight path and the reflected or
image path from the ground plane. In horizontal polarization there is
also 180 degree phase shift due to conservation of charge physics
I read in !emc-pstc that drcuthb...@micron.com wrote (in E6F64B42266D6
54b80a0f7f4b98212a50f3...@ntxboimbx03.micron.com) about 'another OATS
question' on Mon, 23 Jun 2003:
This method makes a DUT look hotter than it really is and makes the site
uncertainty appear larger.
Yes, well, for some
Amund,
CISPR 24 (and EN 55024) provides reasons to not perform various tests, but ESD
doesn’t have any of these “outs”. I think you are entirely correct in
wanting the test done. Like you, I have seen this to be one of the more
applicable immunity tests (along with surge) and we test to
ESD has always been in my view, one of the most applicable EMC tests . We
tests all our products with higher levels than stated in the standards.
Last week I visited a local test lab and they told me that . you do not
need to ESD test your new equipment because it will not be operated (no
Okay,that clears it up for me. I need to take a look at the NSA method. There
has been much talk in articles and on the web about the flaws in the NSA
method.
Dave Cuthbert
Micron Technology
From: Cortland Richmond [mailto:72146@compuserve.com]
Sent: Monday, June 23, 2003 12:09 PM
To:
Dave Cuthbert (drcuthb...@micron.com) wrote:
If I understand the OATS cal procedure, the RX antenna height is moved
from 1 meter to 4 meters and readings are taken. Now this is the strange
part: The readings are averaged. Is this right? Now think about it- when a
DUT is tested, the RX antenna
I have to confess to complete ignorance here. I had no idea that the
measurements made during a height search were averaged. I though the NSA
curve was based on a specular reflection from a perfect ground plane, in
which case only the peak measurement during a height scan could correlate to
the
I think that NSA is done with the maximum over a height scan as well, hence
the Spec Ana is good because you can put it on max hold.
Luke Turnbull
drcuthb...@micron.com 06/23/03 05:40pm
Yes that will work too. I like the SNA or VNA because they calibrate out the
cable loss. As I understand
Jan -
In the US:
Refer to NFPA 70 (US NEC), §300.22, especially subPart C for
requirements related to equipment placed in environmental
air spaces. Also refer to UL2043, Fire Test for Heat and
Visible Smoke Release for Discrete Products and their
Accessories Installed in Air-Handling Spaces.
Yes that will work too. I like the SNA or VNA because they calibrate out the
cable loss. As I understand it, one connects the RX and TX antenna cables
together and then performs a two-port cal. Then connect the cables to their
respective antennas and read S21 or S12 (should be the same either
I believe that it has to do with the cable coatings. I believe that the
cable jackets have to have a higher temp rating and that if they burn, they
cannot give off toxic fumes as these would be carried along an air plenum
type ceiling or floor.
Bob Heller
3M EMC Laboratory, 76-1-01
St. Paul, MN
I realize this has nothing to do with EMC but I am hoping someone can
guild me in the right direction. I have been asked to investigate what
would be required to obtain a plenum rating for our equipment (802.11
stuff). If anyone knows where I can find out more informaton as to
what plenum
Hello Tim
At one of our OATS sites we have a pit under a metal hatch in the
groundplane, to the rear of the EUT turntable. To do the NSA we
put the signal generator down there and connect it back to the
control room via a fibre optic/GPIB link. I wrote some software
which steps the sig gen
Alex
Is the device being placed on the market or being given to the customer as
an evaluation unit?
My understanding is that if it isn't being placed on the market then CE
marking isn't required - as the principle of CE marks is about the free
movement of goods for sale. However, the product must
Hi Group,
If a distributor and/or customer states that they are willing to take the
responsibility of placing pre-CE Mark products in a real application so that
they can carry out a field trial:
1. In this scenario, who is ultimately responsible for placing the non CE
Mark products in the field
Or a Spectrum analyser with tracking generator.
drcuthb...@micron.com 06/20/03 06:58pm
Renting a VNA or SNA would really speed things up.
Dave
From: emcp...@aol.com [mailto:emcp...@aol.com]
Sent: Friday, June 20, 2003 10:02 AM
To: emc-p...@majordomo.ieee.org
Subject: another OATS
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