Don Foreman wrote:
On Sun, 18 Jan 2009 07:57:48 -0800, Winston
wrote:

Don Foreman wrote:
On Fri, 16 Jan 2009 22:30:33 -0600, Don Foreman
wrote:

I didn't get to TIG today. I'll do that tomorrow. Today I did more MIG
tests. I was surprised at how low the fields were. My findings
indicate that anything within the capacity of the machine (Millermatic
210) will be well below the 1 gauss guidline, given careful dressing
of cables -- torch lead and ground cable.
(...)

Excellent news, Don!

Have you discovered arrangements of cables, settings of the welder,
position of body, etc. that result in unacceptably high field strength?

Well no, but I've no doubt that such arrangements exist. I was
careful to arrange cables to *minimize* field strength. I then used
body positions and welder settings that I normally use while welding.

If you discover that you cannot generate a field anywhere near
the guideline even with cable dress that *looks* like it
would be dangerous to an ICD user, that would be useful info for
you, post-op. You need to discover what kinds
of arrangements and settings you'll need to avoid, post-op, if any.

Maybe that 'common mode' mitigation is as important as you and I
think it is. Perhaps not. Post-op is not the time to uncover the
critical variable.

You've seen the FCC EMI passband charts, I'm sure.
Clearly there must be an equivalent susceptibility chart for the
ICD in question. 'Static field' and '60 Hz' field strengths are useful
info but it would be much more useful for you to know the field strengths
that could be troublesome for all the other frequencies as well.



--Winston