Rick,
We manufacture "light sources" that are used to inject a known amount of
light into a fiber optic cable under test. Our high cost models use lasers
and our low cost models use LED's. When it comes to these light sources, we
do indeed consider EN 60825-1 for both the laser and LED models.
We calculate the accessible emissions and classify the devices according to
EN 60825-1. Our LED light sources have more accessible emissions than a
simple LED indicator on an instrument panel, but they still fall into Class
I. As such, we label them as Class I LED Devices. The reason that we take
caution with these products is because they take the harmless emissions from
an LED and focus it into a fiber. A user staring into the output fiber
would be exposing theirself to a very focused emission which is more
dangerous than the unfocused emissions from a single LED. Also keep in mind
that the LED's we use for fiber optic light sources are in the infra-red
spectrum. This means that the user could be staring into the end of an
active fiber and have no idea that they are being exposed to LED radiation.
This may be above and beyond the standard because EN 60825-1 has a clause
that says that Class I devices are exempt from the requirements of the
standard. Even so, the standard goes on to list labeling, marking and user
manual requirements for Class I devices. I never could figure out why the
standard lists a bunch of requirements for Class I devices and, at the very
beginning, says that Class I devices are exempt. In my state of confusion,
I have erred to the side of caution. We try to follow the requirements and
then self declare to EN 60825-1 on our Declaraiton of Conformity.
Having said that, we do make some other products, such as power meters,
which use single red or green LED indicators on the front panel and nothing
else. These LED's are used in their "natural" state, meaning that their
light output is diffuse and unfocused. They are also within the visible
spectrum which means that the blink reflex would take over if a person
sensed that they were too bright. For these products, we do not bother with
any EN 60825-1 compliance. I think that these products have been proven
safe by the fact that billions (OK maybe just millions) of people have been
exposed to single LED indicators with no documented ill effects. In this
situation wouln't worry unless I had a product that had a large array of
LED's such that the accumulated accessible emissions became large enough to
be a concern. If this is the case, EN 60825-1 has some examples for how to
calculate the accessible emissions from an LED array.
I hope this helps. If nothing else I hope that I may have brought you up
from a state of total confusion to my state of
somewhat-confused-but-willing-to-give-an-opinion. :-)
Chris
> -----Original Message-----
> From: ricklinf...@phobos.com [SMTP:ricklinf...@phobos.com]
> Sent: Thursday, March 09, 2000 1:33 PM
> To: emc-p...@majordomo.ieee.org
> Subject: IEC 825 and Light Emitting diodes.
>
>
> Hi group,
>
> When evaluating IEC 825-1 for fiber optic LAN transceivers I came across
> requirements for LED's. I have known that the EU had some requirements for
> LED emission. Being on the US side of the pond I have not seen how it is
> applied.
>
> Are manufactures doing fault testing on LED to ensure the class 1 levels
> are maintained?
> Are manufacturers labeling products with LED's (this covers just about
> every electronic product I know of) with the "CLASS 1 LED PRODUCT" as
> required in 5.12 of IEC 825?
>
> Rick Linford
>
>
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