Date: Tue Mar 31 13:13:36 2009 Back to Contents ------------------------------------------------------------------------

Author: Bernard Cleyet

Subject: Re: LED photoelectric effect apparatus

Post:

It didn't occur to me that one was using LEDs. I thought they were
the detector. Use a Hg lamp -- especially as I still have a bunch of
those light sanitizers for $15. Tho they may not have sufficient
intensity

bc


On 2009, Mar 31, , at 09:25, Andy Dougherty wrote:

> On Mon, 30 Mar 2009, John Welch wrote:
>
>> Hey all -
>> we're making several homemade PE experiments using LED's, based on
>> the
>> article by Wayne Garver in the May 2006 Physics Teacher.
>
> I looked at doing this too, but I made the "mistake" of trying to
> measure
> the actual wavelength of the LEDs I had at hand, rather than
> relying on
> the manufacturer's value. The LEDs had an extremely broad
> distribution of
> wavelengths, easily verified by looking at one through a student
> spectrometer. I've placed a graph at
>
> http://www.lafayette.edu/~doughera/other/lab/LED-Green.png
>
> This doesn't answer the question about the phototubes, of course,
> but does
> make one wonder just what is actually being measured.
>
> --
> Andy Dougherty doughera@lafayette.edu
> Dept. of Physics
> Lafayette College, Easton PA 18042
>


From tap-l-owner@lists.ncsu.edu Tue Mar 31 13:13:36 2009

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