Date: Tue, 9 Nov 93 16:08:00 CST
Subject: Humidity; SAMX; XYZ points
From: johnf@ice

Here are three recent communications /queries from SX50 users. If
anyone has suggestions for Jinny Sissons, please contact her.

========================================================================

Date: Thu, 4 Nov 93 09:50:18 EST
From: "Neil S. Summer"
Reply-To: "Neil S. Summer"

Subject: High humidity and arcing in SX50

This summer we had a corona discharge which our grounding did not
dissipate. After major expediture including our full service agreement
time, we are not entirely back up. SO make sure that your Probe lab stays
within Cameca environmetal spec...humidity <60%; temperature 70!(+-2).
Thedischarge was facilitated by high humidity and some questionable wiring
(the ground should be <3 Ohm). We depended on building air, now we are
insisting on our own indepedant air conditioning and a single instrument
ground isolated fromthe building grid.

More details:

The corona discharge which cascaded through our boards, blowing chips
(but
not fuses) started in our vacuum power supply. The logic board from that
power
supply was sent up to Sam at Cameca ( I am trying to save money by sending
them
the boards for repair). Our major problems lay in these boards (in
descending
order): vacuum power logic, vacuum logic, Ion pump power supply, HV CRT#1,
video1 & 2 and Numeric 1.

An Aside: A cooling water junction exists inside the large cabinet above
the
main and monitor power supplies. With high humidity, the temperature
differential between room air and cooling water can lead to condensation on
the
hose and droplets of water directly into these power supply units.

SO: a) Keep humidity below 60%
b) have only a 10 degree differential between room air and cooling
water
temp.
c) Run your hands under eposed cooling water pipe to check for
condensation.

We will have a single instrument ground fitted (with ground rods) and
an
independant cooling system. In addition we have two dehumidifying units to
kick
in when humidity reaches 60%. I did not do a test but saw the electrician
assess
the resistance between the ground and the SX50 chassis.

All the best, Neil

Neil S. Summer
Department of Geological Sciences,
University of South Carolina,
Columbia, SC 29208

TEL (803) 777-6300
FAX (803) 777-6610

Summer@probe.geol.scarolina.edu

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Date: 7 Nov 1993 10:23:33 -0800
From: "Roger Nielsen"
Subject: Upgrading SX50 operating system

I just wanted to pass out the word that we have gone with the SAMX
Windows
based upgrade, largely because of uncertainty in the future of CAMECA
supported
(and I use the term in the most general sense) upgrades. In addition, it
was
significantly cheaper. I will be at AGU and am willing to talk about our
upgrade options.

================================================================

Date: Tue, 9 Nov 93 11:59:58 CST
From: jinny sissons
Subject: Quantiview

We have a problem storing large numbers of lines in the X,Y,Z part of
the
program. Have you ever tried to import X,Y,Z files into Quantiview? We
are
trying to do this as some users have these set up from other sources and
don't want to manually enter the 100 points they have stored.

We have a beta version of Quantiview installed by Andy Davis for demo
of our
machine about a year ago. When we put in lines it does not sometimes save
the
data from the previous line and we have to go back in and reenter the end
points. It does not seem to be a systematic error. We told Andy about
this
problem last fall. I want to be sure that this has been corrected as it is
a
nuisance. We have no problems with storing large point files to run
overnight.
We don't have the problem that you mentioned with calibrate going to the
wrong
standard.

Jinny

============================================================================
====

John Fournelle
Electron Microprobe Lab Internet:johnf@geology.wisc.edu
Dept of Geology & Geophysics Telephone: (608) 262-7964
University of Wisconsin Fax: (608) 262-0693
1215 West Dayton Street Amateur radio: WA3BTA/9
Madison, WI 53706 (14.030, 21.030 mHz)