Science Project Advice

Hello!


My name is Andrew. I am ten years old.
I am doing a science fair project on EMFs in cars. Can you please help me
with my experiment. What meter should I use for my experiment?


Thank you,
Andrew

PS: This is my mom's address....you can also send the response to my e-mail
at: [hidden email]


[Non-text portions of this message have been removed]

Hi Andrew,

You will find both AC and DC magnetic fields in a car.
Therefore, you can use an AC Gaussmeter and/or a DC Gaussmeter
See http://www.lessemf.com/gauss.html and
http://www.lessemf.com/dcgauss.html respectively.

Emil

----- Original Message -----
From: <[hidden email]>
To: <[hidden email]>
Sent: Friday, November 18, 2005 9:40 AM
Subject: [eSens] Science Project Advice

e-mail

Andrew,

A Trifield meter ($150?) is useful for measuring electric fields
around
coils and spark plugs. It is also useful for measuring magnetic flux
(Gauss) from ignition coils, window and roof motors, central locking
actuators, fans, relays, alternators, wiring, batteries and wheels.
As
the Trifield's magnetic scale is tuned to 60Hz (50Hz for UK versions)
the readings will not be true values but will give you an indication
of
where to look with more sophisticated meters tuned and calibrated to
the sorts of frequencies coming from each device. You may get high
magnetic readings from wiring and batteries which are supposed to be
12v DC (and therefore should read zero on Magnetic and too low to be
read on the Elelctric scale)but the rectified output from alternators
is unlikely to be very smooth producing an AC ripple throughout the
wiring and body shell. As the body is used for the return path, any
AC
current present will be unbalanced. This can create hot-spots
throughout the vehicle. The battery is used as a giant capacitor and
is
used to clean up the supply with varying degrees of success.

A good and relatively cheap meter to detect the magnetism from wheels
is the Cell-Sensor ($49?) with remote magnetic probe which is useful
because you don't have to be near the source if you mount it on a
wooden stick. It is less narrowly tuned than the Trifield and better
at
picking up the lower frequencies of the rotating wheels. You can also
stick the sensor head near various sources easily with Blu-Tak.

There are other sources of vehicle EMF less well known. Under dash
Bluetooth transmitters for detecting the presence of child seats in
the
front. The Micro-Alert ($90?)should show these up but as it chirps
(it
does not have a scale) it will not give you any values. Imobiliser
transmitters which interrogate a transponder chip in the key and air-
bag systems once armed produce a constant signal (at 200Hz I
believe).
If for any reason the signal is lost (as in an accident when the
impact
sensors break contact) then the airbags deploy.

Then there is RF remote central locking (Some systems use Infra-Red)
Anti collision systems use radar beamed at the car in from (Top end
Cadilacs, Mercs, BMW's and others have these) and the newer halogen
headlights too I believe put out some kind of EMR forwards. Satellite
tracking - the little stubby ariel above the rear window or cell-
phone antennas (some through the glass).

Sports cars sit near the ground and regular trips over buried power
cables can affect some people.

Modern cars have an IP network running round them but I'm afraid I
don't know very much about those. Hopefully someone else will.

Galileo

thats a lot of stuff.

--- In [hidden email], "galileo3315" <galileo1564@b...> wrote: versions)
> the readings will not be true values but will give you an indication
> of
> where to look with more sophisticated meters tuned and calibrated to
> the sorts of frequencies coming from each device. You may get high
> magnetic readings from wiring and batteries which are supposed to be
> 12v DC (and therefore should read zero on Magnetic and too low to be
> read on the Elelctric scale)but the rectified output from
alternators
> is unlikely to be very smooth producing an AC ripple throughout the
> wiring and body shell. As the body is used for the return path, any
> AC
> current present will be unbalanced. This can create hot-spots
> throughout the vehicle. The battery is used as a giant capacitor and
> is
> used to clean up the supply with varying degrees of success.
>
> A good and relatively cheap meter to detect the magnetism from
wheels
> is the Cell-Sensor ($49?) with remote magnetic probe which is useful
> because you don't have to be near the source if you mount it on a
> wooden stick. It is less narrowly tuned than the Trifield and better
> at
> picking up the lower frequencies of the rotating wheels. You can
also
> stick the sensor head near various sources easily with Blu-Tak.
>
> There are other sources of vehicle EMF less well known. Under dash
> Bluetooth transmitters for detecting the presence of child seats in
> the
> front. The Micro-Alert ($90?)should show these up but as it chirps
> (it
> does not have a scale) it will not give you any values. Imobiliser
> transmitters which interrogate a transponder chip in the key and
air- Satellite