led & eye safety

R

R.Lewis

Guest
EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?
 
On Thu, 3 Mar 2005 18:59:10 -0000, "R.Lewis" <h.lewis@connect-2.co.uk>
wrote:

EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?
Click to expand...
What about a candle?

John
 
The class definition is for lasers. LED sources are generally safe
because they can be shut off in time by the blink reflex. An exception
is for radiation outside the visual bandwidth.
 
It is the power density that is the thing that is important. A laser has a
very high power density as the beam is not spread out like a LED or
incadesent source is.

--
Why isn't there an Ozone Hole at the NORTH Pole?
 
I read in sci.electronics.design that Bob May <bobmay@nethere.com> wrote
(in <1109882482.57294@news-1.nethere.net>) about 'led & eye safety', on
Thu, 3 Mar 2005:
It is the power density that is the thing that is important. A laser has a
very high power density as the beam is not spread out like a LED or
incadesent source is.

--
Why isn't there an Ozone Hole at the NORTH Pole?


I'm not sure that there isn't, but basically the temperatures in the
Click to expand...
upper atmosphere are not right.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
I answered this ozone problem previously.

It is the unstable wind patterns in the northern hemisphere due to the
assymetrical land masses that clears away any stable layers required
for an ozone hole to persist. However, if polutants continue to
increase, a semi stable hole will appear in the north. There is
already some evidence of this.
 
In article <1109885354.999191.241160@z14g2000cwz.googlegroups.com>,
rrllff@yahoo.com says...
I answered this ozone problem previously.

It is the unstable wind patterns in the northern hemisphere due to the
assymetrical land masses that clears away any stable layers required
for an ozone hole to persist. However, if polutants continue to
increase, a semi stable hole will appear in the north. There is
already some evidence of this.
Click to expand...
Which appears to be ol' Sol playing tricks rather than hairspray.
Better get him to clean up his act!

http://www.livescience.com/forcesofnature/050301_ozone_thinning.html

--
Keith
 
<rrllff@yahoo.com> wrote in message
news:1109878252.035390.90440@g14g2000cwa.googlegroups.com...
The class definition is for lasers. LED sources are generally safe
because they can be shut off in time by the blink reflex. An exception
is for radiation outside the visual bandwidth.

No.
Click to expand...
The class definition is for lasers *and* leds.

(note that 608325 is not for incandescent lamps so please read '1 lumen led'
for '1W incandescent lamp' in my original post.)
 
On Thu, 3 Mar 2005 16:41:35 -0500, the renowned Keith Williams
<krw@att.bizzzz> wrote:

In article <1109885354.999191.241160@z14g2000cwz.googlegroups.com>,
rrllff@yahoo.com says...
I answered this ozone problem previously.

It is the unstable wind patterns in the northern hemisphere due to the
assymetrical land masses that clears away any stable layers required
for an ozone hole to persist. However, if polutants continue to
increase, a semi stable hole will appear in the north. There is
already some evidence of this.

Which appears to be ol' Sol playing tricks rather than hairspray.
Better get him to clean up his act!

http://www.livescience.com/forcesofnature/050301_ozone_thinning.html
Click to expand...
And here are some claims (published in New Scientist) that
hydroelectric power can more greenhouse gases than burning fossil
fuels.

http://www.newscientist.com/article.ns?id=dn7046


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
On Thu, 03 Mar 2005 20:58:10 +0000, John Woodgate wrote:

I read in sci.electronics.design that Bob May <bobmay@nethere.com> wrote
(in <1109882482.57294@news-1.nethere.net>) about 'led & eye safety', on
Thu, 3 Mar 2005:
It is the power density that is the thing that is important. A laser has a
very high power density as the beam is not spread out like a LED or
incadesent source is.

--
Why isn't there an Ozone Hole at the NORTH Pole?


I'm not sure that there isn't, but basically the temperatures in the
upper atmosphere are not right.
Click to expand...
The Earth's north and south magnetic poles attract opposite polarities
of solar wind particles, so the auroras (which are actually the culprits)
work differently in the North and South.

And the other thing is, that whole ozone hysteria is a crock of
propaganda.

Cheers!
Rich
 
In message <pan.2005.03.03.23.30.29.732163@example.net>, Rich Grise
<richgrise@example.net> writes
And the other thing is, that whole ozone hysteria is a crock of
propaganda.
Click to expand...
If you really think there's a shortage of ozone, then my website has a
few details on making some more using nothing more than an old neon
transformer, some stainless steel fly screen and a bit of glass out of a
cheap picture frame. Of course, how you get the ozone up there once
you've made it is up to you. :)

--
Clive Mitchell
http://www.bigclive.com
 
John Larkin wrote:
On Thu, 3 Mar 2005 18:59:10 -0000, "R.Lewis" <h.lewis@connect-2.co.uk
wrote:

EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?


What about a candle?

John
Click to expand...

The sun should simply be banned!



--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarleRemoveThis@BOGUSsandia.gov
NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.
 
On Thu, 03 Mar 2005 17:11:32 -0800, the renowned Chris Carlen
<crcarleRemoveThis@BOGUSsandia.gov> wrote:

John Larkin wrote:
On Thu, 3 Mar 2005 18:59:10 -0000, "R.Lewis" <h.lewis@connect-2.co.uk
wrote:

EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?


What about a candle?

John


The sun should simply be banned!
Click to expand...
That's what Ray-Bans are for!


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
In article <38p531F5rmaddU1@individual.net>, R.Lewis wrote:
EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?
Click to expand...
Many incandescent lamps exceed Class 1 (.4 microwatt in the
400-1500 nm band being able to enter a pupil 7 mm wide and be focused onto
a spot on the retina of angular size smaller than .0002 steradian will
exceed Class I if I correctly read and understand 21 CFR 1040.1)

In the USA, the regulation by the Center for Devices and Radiological
Health that defines these classes does not have regulatory force on light
sources other than lasers, including not on incandescent lamps nor LEDs
if I understand correctly. In addition, Class 1 does not require a label
even for lasers if I read and understood 21 CFR 1040.1 correctly.

- Don Klipstein (don@misty.com)
 
I read in sci.electronics.design that Clive Mitchell
<clive1@emanator.demon.co.uk> wrote (in <4IoF77AOg6JCFwc1@emanator.demon
..co.uk>) about 'led & eye safety', on Fri, 4 Mar 2005:
In message <pan.2005.03.03.23.30.29.732163@example.net>, Rich Grise
richgrise@example.net> writes
And the other thing is, that whole ozone hysteria is a crock of
propaganda.

If you really think there's a shortage of ozone, then my website has a
few details on making some more using nothing more than an old neon
transformer, some stainless steel fly screen and a bit of glass out of a
cheap picture frame. Of course, how you get the ozone up there once
you've made it is up to you. :)

Just make He6O3; the helium will make it float up to the stratosphere,
Click to expand...
where it will conveniently decompose.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
In article <4C$7GsBBlAKCFwEA@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk says...
I read in sci.electronics.design that Clive Mitchell
clive1@emanator.demon.co.uk> wrote (in <4IoF77AOg6JCFwc1@emanator.demon
.co.uk>) about 'led & eye safety', on Fri, 4 Mar 2005:
In message <pan.2005.03.03.23.30.29.732163@example.net>, Rich Grise
richgrise@example.net> writes
And the other thing is, that whole ozone hysteria is a crock of
propaganda.

If you really think there's a shortage of ozone, then my website has a
few details on making some more using nothing more than an old neon
transformer, some stainless steel fly screen and a bit of glass out of a
cheap picture frame. Of course, how you get the ozone up there once
you've made it is up to you. :)

Just make He6O3; the helium will make it float up to the stratosphere,
where it will conveniently decompose.
Click to expand...
Hmm, He6O3 has a molecular weight of 72. Me thinks this idea won't
float.

--
Keith
 
In any safety document you have to watch your shoulds and shalls.
"Shall" means you must. "Should" means it is a good idea if you do
this. To quote from the 60825-1 manual section 5.2

Class 1
Each class 1 laser product SHALL have affixed an explanatory label
(figure 15) bearing the words:
CLASS 1 LASER PRODUCT
or instead, at the discretion of the manufacturer, the same statement
may be included in the information for the user.

--end quote--

To interpret this means you MUST either put a label on the device or
include the same verbiage as the label in the user manual.

60825-1 is for Lasers
60825-2 is for optical comm systems that include LEDs or lasers

Neither document covers incandescent illumination. Hazard calculations
are based on power per unit area per unit time and are wavelength
dependent. Do NOT do these calculations unless you fully understand
them. If you miscalculate in the wrong direction you could loose an eye.

Best Regards,
P. Danek

Don Klipstein wrote:

In article <38p531F5rmaddU1@individual.net>, R.Lewis wrote:

EN60825-1 is a bit of a quagmire (to me anyway).

For a class1 device I believe that no label is required to be fixed to the
product but in the instructions and/or manual there should (must?) be a
reference to it being class 1.

Is this correct?

Does this mean that, say, a simple torch (with a 1W incandescent lamp - way
way below the limits of class1) needs to be referred to as class 1 in its
instructions?
What if there are no instructions?
Must there be some just for somewhere to write class 1 ?


Many incandescent lamps exceed Class 1 (.4 microwatt in the
400-1500 nm band being able to enter a pupil 7 mm wide and be focused onto
a spot on the retina of angular size smaller than .0002 steradian will
exceed Class I if I correctly read and understand 21 CFR 1040.1)

In the USA, the regulation by the Center for Devices and Radiological
Health that defines these classes does not have regulatory force on light
sources other than lasers, including not on incandescent lamps nor LEDs
if I understand correctly. In addition, Class 1 does not require a label
even for lasers if I read and understood 21 CFR 1040.1 correctly.

- Don Klipstein (don@misty.com)
Click to expand...
 
rrllff@yahoo.com wrote:

The class definition is for lasers. LED sources are generally safe
because they can be shut off in time by the blink reflex. An exception
is for radiation outside the visual bandwidth.
Click to expand...
Last time i checked, the "blink reflex" was a tad slower than LED
light.
Also, LED light travels just as fast as laser light?
 
It's not the speed of light that matters it's the illumination value on
the retina. A laser is a point source which creates a diffraction
pattern of very high illumination on the retina. An LED is an extended
source which does not.
 
And the other thing is, that whole ozone hysteria is a crock of
propaganda.

That's about the size of it!
Click to expand...
BTW, the posts here are probeably the best on the subject! Everyplace else
that comments on my sig. really tend to believe that there is a real
probleem with CFC production causing the ozone hole without realizing some
little facts about the loss of ozone.
There is a little volcano in the Antartic that is constantly venting and the
gasses from that volcano are doing more to reduce the ozone levels theree
than anything that we humans are doing.
The major producion/usage of the various ozone "depletion' chemicals has
been done here in the northern hemisphere yet the "big" problem is not there
but the furthest away from that production and usage of those chemicals.


--
Why isn't there an Ozone Hole at the NORTH Pole?
 
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