Posted by bbin37 on Aug 09, 2004; 9:01pm
URL: https://www.es-forum.com/Hi-Folks-tp1536584p1536587.html

--- In [hidden email], "David Fancy" <davidfancy@h...> wrote:
<snip>
> I'm concerned about automobiles.
<snip>

Hi, David,

Here's a link to a short discussion on the electrical systems of
gasoline and diesel cars and other good info from an ES engineer:
http://www.ctaz.com/~bhima/emf.htm

Also, most car tires are "steel-belted", i.e., reinforced with steel
wire that is magnetized. When spinning they can generate extremely
low frequency alternating fields, usually below 20 Hz. These fields
have been measured at 2.0 microtesla (20 milligauss) at seat level in
the passenger compartment. See:
http://www3.interscience.wiley.com/cgi-bin/abstract/65500812/ABSTRACT
Getting non-steel-belted tires is still possible.

Like Marc, I drive a 10-year old car. The interior's magnetic field
is in the 0-5 milligauss range, strongest near the front floorboard,
and depends on conditions and use. (The meter I use for measuring
this is a TriField meter; see www.trifield.com. It takes into account
all three field polarization directions at once, and it is
frequency-weighted combining the effects of frequencies from 30 Hz to
500 Hz. The reading it gives therefore closely approximates the bulk
field strength on the body for the frequencies the meter can measure.)

I'm taking extra care to extend my car's life since I've noticed that
car interior magnetic fields have dramatically increased in the last
couple of years -- so much so that I can't drive most recent models.
On a trip last year, I tried to get a rental car that was bearable for
short intervals. I measured the fields in many compact and mid-size
vehicles and couldn't find any that were suitable. Fortunately, I
found an SUV that had lower EM emissions; why, I don't know. I'm
hoping to get some info from a car wizard friend on what year to buy
at, or before, to avoid lots of electronics in a car. I'll pass it
along when I hear from him on this.

Regards,
Beau