We took delivery of a 252 in August 1994.  Since that time 2 Balzers
06x (Source and Wasteline) died under warrantee and were replaced.
The controller on the Wasteline turbo also failed when the pump
self-destructed, and the unit that was sent out to us was faulty too.
Subsequently the replacement Wasteline turbo failed and the turbo on
the Kiel device destroyed itself.  We replaced the Wasteline pump and
controller with Varian components which were cheaper, not made by
Balzers, and have run fine for 2 years.  The Kiel device now uses a 30
year old 2 inch diffusion pump instead, which does the job without
fuss.

After the demise of 4 Balzers model 06x turbos there have been no more
failures for 2 years, but our initial experience was so alarming that
we seriously questioned our choice of mass spec, and probably
influenced the choice of all that we spoke to.  Since that time we
have grown to like our 252 very well, despite its many quirks and its
quaint software.

While on the subject of pumps, I should add that our experience of
Edwards model 1.5 rotary vacuum pumps has been dismal.  We have
replaced them all (some more than once) for various reasons,
breakages, burnouts and massive oil leaks.  I have put E2M2s on the
Kiel device and will soon replace the last 1.5 in the 252 with a
larger pump.  I was warned that these were useless pumps, now I
know. We have many of the larger model pumps and these have all been
very reliable and I would recommend them to anyone.  But those
pathetic, silly little one-point-fives ......................!

All the best
John





******************
John Lanham    -   Stable Light Isotope Laboratory
Archaeology, University of Cape Town, South Africa
Tel: +27 21 650 3847
Fax: +27 21 650 2352

World Archaeology Congress, Cape Town, January 1999
http://www.uct.ac.za/depts/age/wac