Re:ATM Wire test

["Tom Krajci" <tkrajci@san.osd.mil>]

From: kwhitefire@juno.com

>Wire test according to Kevin, Seeker of the Darkness:
>(I may be wrong, but it seems to work)

>Substitute a wire (I use a hair) for the knife edge.  Use a couder
screen.  >Numbers as with a Focault test.

There is no absolute need for the couder screen if you use a pinstick.
For the Foucalt test the screen helps identify where you should look on
the mirror.  A pin stick will do the same job for the wire test, and is
easier to fabricate...especially if you want to experiment with
measuring more or fewer zones on the mirror.  (If you test many zones on
the mirror with the wire test...you may want to use some way to
identify/highlight which pin you are making the measurement
for...perhaps a penlight or laser pointer shining on the pinstick just
below the pin on which you are interested in taking zonal measurements.)

Once you do the wire test, then put a knife edge back in place, and
check your overall smoothness by nulling all the zones, and check to see
if you have a diffraction ring all 'round the mirror.  Then put a ronchi
grating in place and look at the overall figure and evidence of turned
edge.

Tom Krajci
Tashkent, Uzbekistan

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.419 / Virus Database: 235 - Release Date: 11/13/2002