Thanks to all who responded to my question regarding the removal of zirconia caps from
MAS rotors and the feasibility to use the much cheaper Kel-F rotors at low temperatures.
To summarize the results:
1.)
Zirconia caps my be removed by cooling the rotor + cap (either by dipping into liquid nitrogen
or by using a cooling spray). Using Bruker's special tools for the cap removal should also help.
Nevertheless, these caps tend to break frequently, sometimes even when put on the rotor.
2.)
Kel-F caps may be used between -30 and +80 Centigrade. Attempts to use them at -50 have lead
to caps flying off the rotor while spinning and worse.
Regards,
Hanno Leisen
_____________________________________________
Dr. Johannes Leisen
Research Scientist II
Georgia Institute of Technology
School of Textile and Fiber Engineering
Atlanta/GA 30332-0295
phone: (404)894-9241; FAX: (404)894-9766
e-mail: johannes.leisen_at_textiles.gatech.edu
Received on Tue Jun 05 2001 - 10:53:40 MST