Rich,
Your case is off chart 2X scale wise of my direct experience, but I'll share
anyway. (Our best one was the facility not knowing the MR lab was adjacent
to an underground rail line power distribution scheme).
Could be a 2 part problem:
Part 1. is the difference between 'before' and 'after', they run the lines,
even if 'after' is a stable case. You may have 'adjustments' effects.
Part 2. would be in the after case, in the new steady state, any effects if
they were not 'one time'.
Part 1. That level power distribution is usually done inside fully enclosed
metallic conduit with serious grounding, albeit the grounding is for safety
and not EMF interference really. I would suggest that you attempt to engage
the electrical contractor and see if he will take you to any like electrical
scale site/situation and you can poke around and do some empiric testing
adjacent.
Part 2. The good news is that it is for a supercomputing facility and not a
welding shop for an open pit mine.which means at least that the load and
current flowing in the lines should not be changing by orders of magnitude
within the Tr's of your experiments. Even so, there may be measurable
effects that you would see in the above testing. If it were me, I might be
guessing more magnetic field effects than 60Hz noise.
It sounds like the spacing is really close. I'm guessing it will be digital,
either it sounds scary but works fine after some compensation, or else it is
just a really bad idea.
(Or, you could just go over to McGuckin hardware and pick up a "really big
AC line shielding gizmo Adapter for HFNMR machine" for $19.99.aisle 7 I
think..)
best,
Richard
Richard Hullihen
m2m Imaging Corp
190 Alpha Park
Highland Hts OH 44143
440-684-9690 tel
440-684-9695 fax
440-463-6642 cell
_____
From: Richard Shoemaker [mailto:Richard.Shoemaker_at_colorado.edu]
Sent: Thursday, January 21, 2010 8:01 PM
To: ammrl_at_ammrl.org
Subject: AMMRL: Interference from High Voltage Power Lines?
Dear All:
I know certain issues have been addressed about the impact of new
utilities/services near existing NMR laboratories, but I'm not sure this one
has been discussed exactly. If anyone has any real-world experience that
might help us to understand the possible impact of this I would appreciate
hearing from you. I will, of course, summarize any useful information that
I receive.
Here is the issue:
Just outside our 800MHz NMR facility, they plan to install a new
supercomputing facility that demands a lot of power. Due to the location,
the current proposed plans have them running the AC power feed just outside
the NMR lab. My concern is EMI interference that would be picked up in
various ways by the NMR console, probe, cables, .etc. The power lines will
be carrying 480 VAC, 1000kVa, 1200 Amps. One of the plans has the power
lines going through the building just behind the wall where our console is
located, and another would site them on the opposite side (maybe 50 feet
from the magnet, and 65 feet from the console).
1) Does anyone have any experience that might suggest whether or not
this will be a problem? I have visions of all kinds of 60/120 cycle
interference showing up in strange ways in our data.
2) Does anyone have specific ideas how we could somehow test the
impact, in terms of interference, before they actually build this thing
because after the fact it will be too late?
The combined body of knowledge of this group is mind boggling, so I look
forward to hearing from you. I have already passed this along to Varian,
hoping that they might be also able to assist us in dealing with this.
Thank you in advance,
-Rich Shoemaker
---
Richard K. Shoemaker, Ph.D., Director, NMR Spectroscopy Facility
University of Colorado at Boulder
Phone: (303) 492-7062 Fax: (303) 492-5894
E-Mail: Richard.Shoemaker_at_Colorado.edu
Web: http://chemnmr.colorado.edu/rshoe
Received on Fri Jan 22 2010 - 11:09:14 MST