[ATM] More redundancy

[Michael Coslo]

On Mar 10, 2011, at 12:17 PM, Paul A. Valleli wrote:

> David,
> The problem with IR security cameras is that they
> are only working at 0.7 to 1.1 microns. That is not
> a long enough wavelength change to get a good
> reflection off ground glass. 

<snip>

> ---- Original message ----
> 
>  Date: Thu, 10 Mar 2011 08:25:30 -0800
>  From: David Davis <vorblesnak at gmail.com>
>  Subject: [ATM] More redundancy
>  To: atm at atmlist.net

<more snip>
>> 
>> At the bottom of that page they talk about using
>  infrared to test the figure
>> of a rough grind. That made me think, could I
>  mock that up using an
>> infrared security camera. Do a basic Foucault or
>  Ronchi using infrared and
>> see where my rough grind it.

<more snip>

Considering that it is the rough grind, I can't help but wonder what advantage there would be to using anything more precise than a template. Templates don't have that modern age cachet, but testing "figure" on a rough grind seems like a monumental waste of time.

Only useful thing I can think of is being used as an experimental method to show how much things change, even from wet to wet.

Now having said that, I have a real suspicion that many of us end up with rough grinds of really strange shapes. With all the different methods we use, pipe flanges, cast iron frying pans, small rocks and the like, it wouldn't be surprising.

- 73 de Mike N3LI -