Hi everyone,
This is mostly for Varian Inova-solids users; however, this might also
work for other MAS systems.
I do solids on my Varian Inova-400, with the Varian/Jakobsen style
probes, and I've never been thrilled with using white/black enamel to
mark the bottoms of the rotors. The drying time alone (for the paint)
can be a problem, but sometimes the paint also doesn't adhere well and I
lose the ability to measure the spinning speed in the middle of an
experiment.
The new Metallic Sharpie(r) permanent marker pens have made things
infinitely better. I use a black Sharpie pen for one half, and metallic
silver for the other half. The ink dries almost instantly, and the
marks are indeed permanent. The ink marks survive, even after operating
at temperatures above +160 Deg.C. for extended periods. As long as your
spinning sensor uses Red light through the fiber optic (and not IR), the
metallic/black combinations gives outstanding contrast for sensing the
spinning speed.
Don't try the metallic pen as a replacement for the white dots on your
Varian liquids spinner-turbines. Apparently, the silver appears black
to the IR photodiodes inside the upper-barrel, and it can't sense the
spinning at all.
I just thought this might be useful information to share with others.
Cheers,
-Rich Shoemaker
---
Richard K. Shoemaker, Ph.D.
NMR Facility Director
University of Colorado at Boulder
Phone: (303) 492-7062 Fax: (303) 492-5894
E-Mail: Richard.Shoemaker_at_Colorado.edu
Received on Mon Jan 26 2004 - 09:13:14 MST