From: "Marc Castel" <castel@robosky.com>
To: "Stefan Mochnacki" <stefan@crux.astro.utoronto.ca>
Subject: Re: Grating position limits?
Date: Sun, 12 Jan 2003 15:07:45 -0500


Hi Stefan,

This should be done for each each grating. I did a rough calibration of the
rough grating as follows:

>From my notes of  June 21/02:

Spectrograph Calibration:

Focus Out increases the value of the spectrograph.
a value of 41352 = 11.50 reading on the micrometer - (11.5 Angstroms)

Focus In reduces the value of the spectrograph
a value of   0 = 0.08 reading on the micrometer.

Settings are:

Duty Cycle: 5% (This holds the micrometer in place when not moving - higher
is stiffer)

Microstep Pause: 4
Step Size: 1
Total counts for full out = 41352 (at 11.5A)

Rough formula: Focus Count set = (Desired Central Line in A +
15986.94)/1.104899659

Marc