Rich and Scott -
Irrespective of how any test house decides to address
indicator LEDs, my discussions with TC76 members and
contributing experts, including Bob Weiner and Jerome
Dennis, as well as the remainder of the members at a panel
discussion at the 1997 Laser Institute of America
International Laser Safety Conference, it was not the intent
of IEC60825-1 to apply to faceplate indicator LEDs of
electrical equipment. Rather, the concern was for higher
powered LEDs of up and coming technologies.
It was the consensus of the aforementioned panel that the
LED manufacturer's data sheets should be considered to
provide adequate evidence of compliance, should the question
arise. (One industry representative to the Infrared Data
Association in attendance was particularly vociferous at his
perception of injustice doled out to the lowly LED by
IEC60825-1 and welcomed this as a step in the right
direction.)
It was further discussed that most LED data sheets use units
of Lumens and Candela more often than W, Wcm-2, J, Jcm-2, or
any other set of units found in IEC60825-1. The conversion
is not always straight forward, since the measurements on
data sheets aren't necessarily at the 20cm accommodation
distance or using the measuring system in IEC60825-1, but if
analysis supports compliance without extraordinary dalliance
with the data, that the data sheets can and should be
considered "good enough." ("Can" and "should" are
understood to not imply "will" or "shall.")
Far be it from certification houses to either be privy or
care about the standards committee intent, when they are
applying what amounts to a problematic standard (one hears
how problems certainly didn't end with A11 to EN60825-1).
There are also some certification houses that place so
little faith in manufacturer's data sheets for either LEDs
of diode lasers that they insist on performing wavelength
measurements, in addition to power and energy measurements,
with only the justification of "needing to be certain,"
yielding uncertain value with respect to safety.
I haven't heard from any TC76 member in many months, so if
any members of this list are TC76 members or contributing
experts, please add to this discussion.
Regards,
Peter L. Tarver, PE
Product Safety Manager
Sanmina-SCI Homologation Services
peter.tar...@sanmina-sci.com
> -----Original Message-----
> From: Rich Nute
> Sent: Wednesday, February 20, 2002 10:25 AM
>
> Hi Scott:
>
> > The scope of EN 60825-1 says LEDs are
> included whenever the word "laser"
> > is used, meaning they are to be evaluated the
> same way lasers are. Does
> > this apply to status indicating LEDs
> (non-lasing)? If so, are
> > manufacturers expected to test every
> status-indicating LED on the
> > product as if it were a laser?
>
> Yes.
>
> At least one certification house demands measurement
> data for each indicator LED. Emission class must be
> identified on the product or in the manual. (Note
> that emission class is determined under single-fault
> conditions in the driving circuit.)
>
> However, in practice, other certification houses use
> a get-out for indicator LEDs. Usually this is in the
> form of a "not tested, but may be required by some
> authorities" statement in the report.
>
> Most indicator LED manufacturers do not know of EN
> 60825-1, and have no idea how to test.
>
> Measurement is not easy, especially the determination
> of the aperture.
>
> Most indicator LEDs will open before achieving Class
> 2 emission levels.
>
> The above does not apply to automotive LEDs or to
> traffic signal LEDs.
>
>
> Best regards,
> Rich
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