Hello Huiming,
 if the pumps did not stop working because of some (un)sceduled power
outages, maybe a board or board unit was damaged ?

Best regards and good luck,
 Deborah


At 16:16 10.01.2005 -0600, you wrote:
>Dear folks:
>I found my turbo pump unit (TMH 262 and TMH 071) on the analyzer
>(MAT253) was off this morning. After   restarting, the turbo unit won't
>be able to attain nominal rotation speed, which means that I won't be
>able to check source pressure on the mass spec. The back pump (DUO 5.0)
>are fine (pumping down to 10 ^ -5 torr). No leak on the line is
>detected. A call to Pfeiffer did not seem to indicate that the turbo
>pumps are broken. The turbo pumps have been pumping for 2.5 years, and I
>don't expect their life is that short.
>
>I know several scheduled and unscheduled power outages during the
>holidays were partially to blame, but any suggestion how to fix the
>problem will be appreciated.
>
>Best,
>Huiming
>
>--
>Huiming Bao, Assistant Professor
>Department of Geology & Geophysics,
>E235 Howe-Russell Geoscience Complex
>Louisiana State University
>Baton Rouge, LA 70803, USA
>Tel: 225-578-3419 (office), -3413 (lab)
>Fax: 225-578-2302
>http://www.geol.lsu.edu/bao/
>

*****************************************
*                                       *
* Deborah Rupprecht                     *
* Institut für Pflanzenernährung        *
* Rhein. Friedrich-Wilhelms-Universität *
* Karlrobert-Kreiten-Str. 13            *
* 53115 Bonn                            *
*                                       *
* Tel. +49 -(0)228 -73 -3640            *
*                                       *
*****************************************