Re: using a UV LED as a detector

On Tue, 04 Sep 2007 13:34:55 GMT, AZ Nomad wrote:
On Tue, 04 Sep 2007 10:15:40 GMT, Peter Lynch <pete@xxxxxxxxxxx> wrote:



The plan is to build some sort of meter for measuring the UV light
intensity from the sun. Now I'm not talking about UV-indexes or any sort
of medical/lab-quality measurements, just a hobby level goofing around
project.
I know that a normal LED can be used "backwards" as a detector, so
one option I'm considering is to use an ultraviolet LED, with emmissions
around 395 nm as the detector. I realise it will probably detect
normal light too, but hopefuly with a bit of experimentation using LEDs
of different colours I can take this into account.

Has anyone got any experience of this kind of thing and in particular
will a uv LED actually detect at long-uv wavelengths?

Why don't you just use a proper sensor?
They can be had for around $20:

http://www.mouser.com/search/ProductDetail.aspx?R=PC1-2-TO18virtualkey63510000virtualkey718-PC1-2-TO18

..... and, sadly, another $33 shipping to --------+
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.. never trust a man who, when left alone ...... V .
.. in a room with a tea cosy ...... Marlow, England .
.. doesn't try it on (Billy Connolly) .....................................

However, John holds out some hope that a blue/UV LED will detect at
shorter wavelengths. I guess I'll pick up a variety of LEDs and do a
bit of playing - see what I come up with.

As I said, it's only a hobby project. If nothing comes of it at least
I'll have learned something and had fun in the process

Pete
.

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