> Numare's AC-200 NMR system was installed by Bruker engineers in the summer of
>
> 1994. The system is 1983 vintage with Aspect 3000 computer, array processor,
>
> and process controller. It works fine with one notable expection: The
> preamp housing relays do not work. A second preamp housing sent as a
> replacement has the same problem.
>
> Question: Has anyone had the same problem? Did you work out a solution?
> Any help will be greatly appreciated.
>
We had this problem once with our 1985-vintage AM400. After a bit of
head scratching I demagnetizied the relays, and everything was happy.
Apparently the field from the magnet had magnetizied them to the point
that they were not releasing properly when the current to the relay
coil was cut off.
I used a small demagnetizer as used to demagnetize heads on tape
recorders (from Radio Shack I believe).
The relays are accessable by removing the metal plate at the back
of the relay housing, and they can than be demagnetized in situ.
Cheers,
Deane D McIntyre
NMR Mananger
Dept. Biological Sciences
University of Calgary.
dmcintyr@acs.ucalgary.ca