Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

PPMA attenuation coefficient

30 views
Skip to first unread message

mika

unread,
Nov 29, 2009, 3:24:32 AM11/29/09
to
Hi all,

i want to know, what ist the attanuation coefficient (absorption
coefficient) (x [1/mm]) for clean PPMA on wavelenght by ~ 640 nm
(Red). Where can i found it?

Thanks,
Mika

Lostgallifreyan

unread,
Nov 29, 2009, 3:55:41 AM11/29/09
to
mika <mika...@gmail.com> wrote in news:9aa56bd8-4066-4d56-b486-
5482b0...@s20g2000yqd.googlegroups.com:

Hello. Do you mean PMMA, as in acrylic? If so, as a guide I have a Philips
data sheet stating 90% transmission for an uncoated CAY033-040 lens at 670
nm.

A graph halfway down the page at http://www.zeonex.com/optical_plastic.asp
shows that PMMA has a flat line at 90% through a range wider than that
between 640 and 670, given for a thickness of 3mm, approximately the same
thickness of the CAY033 lens also.

In practise you'll likely find other things more influential on how much
light you get, or lose, than the qualities of PMMA itself.

mika

unread,
Nov 29, 2009, 4:11:41 AM11/29/09
to
On Nov 29, 9:55 am, Lostgallifreyan <no-...@nowhere.net> wrote:
> mika <mikama...@gmail.com> wrote in news:9aa56bd8-4066-4d56-b486-
> 5482b0fb6...@s20g2000yqd.googlegroups.com:

>
> > Hi all,
>
> > i want to know, what ist the attanuation coefficient (absorption
> > coefficient)  (x [1/mm]) for clean PPMA on wavelenght  by ~ 640 nm
> > (Red).  Where can i  found it?
>
> > Thanks,
> > Mika
>
> Hello. Do you mean PMMA, as in acrylic? If so, as a guide I have a Philips
> data sheet stating 90% transmission for an uncoated CAY033-040 lens at 670
> nm.
>
> A graph halfway down the page athttp://www.zeonex.com/optical_plastic.asp

> shows that PMMA has a flat line at 90% through a range wider than that
> between 640 and 670, given for a thickness of 3mm, approximately the same
> thickness of the CAY033 lens also.
>
> In practise you'll likely find other things more influential on how much
> light you get, or lose, than the qualities of PMMA itself.

Hello. Yes i mean PPMA as in acrylic.
My optical path is over 60 mm long. I want to calculaculate
how many power is lost on the path, whit the Beer-Lambert equalation.

Lostgallifreyan

unread,
Nov 29, 2009, 4:39:57 AM11/29/09
to
mika <mika...@gmail.com> wrote in news:54562958-ae86-4aef-a124-
5eb00e...@c34g2000yqn.googlegroups.com:

PMMA, not PPMA. That error might have stopped you getting good search
results. A lot of them are private anyway, but trying PMMA and Beer-Lambert
will find something, hopefully.

mika

unread,
Nov 29, 2009, 2:28:45 PM11/29/09
to


PMMA (acrylic) has 2% absorption per inch, 0.02/25.4 [1/mm] in
visible range

0 new messages