Source for Helmholtz Coils

[mully]

I'm looking for a tri-axial, 1 meter Helmholtz Coil to calibrate a set
of magnetoresistive sensors. I have come this far:

http://www.magnetometer.com/helm3.htm

but have run into potential problems with price and lead time.
I could settle for less than 1 meter. Any solutions?

 

[John Woodgate]

I read in sci.electronics.design that mully <shawn@bluestartools.com>
wrote (in <1107192871.888272.184560@c13g2000cwb.googlegroups.com&gt about
'Source for Helmholtz Coils', on Mon, 31 Jan 2005:

I'm looking for a tri-axial, 1 meter Helmholtz Coil to calibrate a set
of magnetoresistive sensors. I have come this far:

http://www.magnetometer.com/helm3.htm

but have run into potential problems with price and lead time.
I could settle for less than 1 meter. Any solutions?

Why not consider making one? I can supply the basic winding data, if you
want to try.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[John Larkin]

On 31 Jan 2005 09:34:31 -0800, "mully" <shawn@bluestartools.com>
wrote:

I'm looking for a tri-axial, 1 meter Helmholtz Coil to calibrate a set
of magnetoresistive sensors. I have come this far:

http://www.magnetometer.com/helm3.htm

but have run into potential problems with price and lead time.
I could settle for less than 1 meter. Any solutions?

Build one. It's just wire.

John

 

[mully]

Well, that is interesting and then I suppose I would require a
gaussometer and drive circuitry. Unfortunately, the cost in time alone
would likely outweigh the benefit and a high quality/resolution device
is required. This is a commercial venture so often it's best to simply
purchase a tried solution.

I would, however, be interested in receiving your basic winding data,
perhaps as a hobby venture. Shawn

 

[mully]

True, it is simply wire

 

[Tim Shoppa]

If you want a set of 1 meter Helmholtz Coils to calibrate
magnetoresistive sensors, then presumably you've determined that you
need a volume of fairly flat magnetic field with dimensions like 10 or
20 or 30 cm on a side.

If you can live with a substantially smaller area of flat field, you
can use a much more compact non-Helmholtz coil setup and a gaussmeter
to do your calibration between the poles. Gaussmeters are rather
common at used test equipment houses and Ebay.

Tim.

 

[Rene Tschaggelar]

mully wrote:

I'm looking for a tri-axial, 1 meter Helmholtz Coil to calibrate a set
of magnetoresistive sensors. I have come this far:

http://www.magnetometer.com/helm3.htm

but have run into potential problems with price and lead time.
I could settle for less than 1 meter. Any solutions?

Helmholtz coils have a fairly uniform field within a third
of the diameter and a third of the length. They are easy to
calculate and easy to wind yourself.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[mully]

That's valuable information. Thank you.

What is your recommendation for a "more compact non-Helmholtz"
arrangement. Solenoid?

 

[mully]

thanks