IEC 825-1 first edition was published in 1993 and contained requirements
for LEDs in addition to lasers. EN 60825-1 was subsequently published in
1994. I am informed that the method for classification led to LEDs being
incorrectly ascribed a higher class than should be the case (i.e. LEDs came
out to be Class 3A although the optical hazard was at the Class 1 level).
It seems that LEDs were included because the available power from such
devices continues to increase to a point where the optical output from some
LEDs was considered to be an optical hazard. Remember also that IEC 825-1
requires determination of the optical output under both normal and single
fault conditions.
IEC TC76 and CENELEC TC76 both worked to resolve the issue of inappropriate
classification. Within Europe we have A11 to EN 60825 which was published
at the end of 1996 and has a date of withdrawal of 1 Jan 1997. Hence,
technically speaking, under the CENELEC rules, both EN 60825 {no dashes}
and the earlier version of EN 60825-1 have been superseded and should not
be used for new products. There is no certification statement in A11 of EN
60825-1 (c.f. the foreword of EN 60950).
For IEC 950, IEC TC74 have taken the view that they will continue to 'point
to' IEC 825 {no dashes} until TC76 sort out the LED classification issue.
In Europe, there is a draft amendment to EN 60950 (prAC) that 'points to'
EN 60825-1 inc. A11. The proposed date of publication of prAC is 1 June
1998.
I now await the inevitable debate on how products containing LEDs can be
approved or declared to the existing version of EN 60950 (which points to
EN 60825 {no dash}) and yet EN 60825 {no dash} is no longer a valid
standard under the CENELEC rules.
I also hope, and expect, that suppliers of LEDs will be able to provide me
with an analysis and classification that states that their products may be
considered as Class 1 lasers in accordance to EN 60825-1 including A11.
Certainly I do not want to start having to pay for the evaluation of the
little green LED that lets me know that everything is OK and working at the
time of my type test.
So, let the debate commence...
Richard Hughes
p.s. Naturally, if you construed any of the above to be an opinion of any
know living being, or corporate body, or anything else, you would be
entirely wrong.
p.p.s. When we can expect to see a 'disclaimers for dummies' book, or even
better, an Email where you can extract your favourite disclaimer of the
day?
(Not here do I hear Roger Volgstadt saying?)
