🚀 go-pugleaf

On Mon, 13 Aug 2012 19:32:19 +1000, "David Eather"
<eather@tpg.com.au> wrote:

>On Mon, 13 Aug 2012 18:31:17 +1000, Jon Kirwan <jonk@infinitefactors.org>  
>wrote:
>
>> On Mon, 13 Aug 2012 01:18:31 -0700, I wrote:
>>
>>> On Sun, 12 Aug 2012 23:52:09 -0700, Jeff Liebermann
>>> <jeffl@cruzio.com> wrote:
>>>
>>>> On Sat, 11 Aug 2012 23:22:35 -0700, Jon Kirwan
>>>> <jonk@infinitefactors.org> wrote:
>>>>
>>>>> My intent is to only use parts that a student can afford to
>>>>> buy and OWN at home.
>>>>
>>>> Is $30 too much?
>>>> <http://shop.breadpig.com/collections/publiclaboratory/products/desktop-spectrometry-kit>
>>>> <http://spectralworkbench.org>
>>>
>>> Yes, $30 is too much and so is requiring a computer. To start
>>> out, the students build a paper box and use a DVD and just
>>> their eyes.  The DVD is far far less than $1. (20 cents?) The
>>> box is ONE sheet of cardstock (a few pennies.) The glue is
>>> Elmer's and doesn't need much. That's it. The DVD is the only
>>> tricky part. I just prefer the DVD-RW because it doesn't have
>>> a terrible blind spot in the red band (DVD-R absorbs heavily
>>> over a range in there.)
>>>
>>> Some students will then move on to the idea of a camera and
>>> using a computer to process the pixels. There is some work
>>> involved in that next step (I've already written all the
>>> wavelength calibration software, though.) Not all students go
>>> there. Most just stop at the box and use their eyes.
>>
>> P.S. I also see that the above $30 unit specs "better than
>> 3nm spectral resolution." I'm already getting much better
>> than that, being able to easily separate 577nm and 579nm
>> mercury doublet. Easily.
>>
>> Jon
>
>http://www.ebay.com/itm/Holographic-Diffraction-Grating-Glasses-Double-Axis-13-500-l-Specrum-Laser-NEW-/280806590885?pt=LH_DefaultDomain_0&hash=item41616089a5

Yeah. That's still 500 lines/mm. They just made it "look
better" by using inches.

Nope. No interest.

Jon