Looking for GMR sensor manufacturers

[TheKraken]

I'm working in the research side of physics, so truth be told, I'm not as much of an engineer as most people here, but I trust you more than anyone else I've found.

I've been searching for a company that sells Giant Magnetoresistance magnetometers for a while now to no avail. This company (

http://www.gmrsensors.com/)

sells GMR sensors, but they aren't guaranteed to very low temperatures, and they aren't necessarily as sensitive as I'd like.

We want the GMRs to have sensitivities in the micro-gauss range, if possible.

We also want to be able to cool these magnetometers to 4k. I understand GMR sensors tend to actually work better at low temperatures, so maybe that's not really a problem.

I've tried just contacting Hitachi, but they don't sell GMRs individually. If anyone has any insight, I'd really appreciate it.

We're trying to avoid fluxgate magnetometers.

 

[MagMike]

You might want to try the magnetic instrument manufacturers. Here are a couple of suggestions, others may chip in with more:
LakeShore Cryotronics:

http://www.lakeshore.com/index.html

FW Bell (Sypris):

http://www.sypris.com/test-and-measurement/magnetics-fw-bell/fw-bell-products

Walker:

http://www.laboratorio.elettrofisico.com/news.asp?lang=eng&id_news=58

MagnetPhysik:

http://www.magnet-physik.de/

Magnetic Instrumentation:

http://www.maginst.com/

Hope this helps

 

[sreid]

You could play with a read head taken from a Hard Disk Drive.

 

[TheKraken]

Thanks for your help guys!

On first inspection, they don't quite seem to have what I'm looking for. It may just be prudent to do as sreid suggests and bust open a hard drive. It would have to be a relatively modern, fast rpm hard drive, wouldn't it? The technology isn't necessary for slower drives. Or is it cheap enough that they all use GMRs now?

 

[IRstuff]

There's no such thing as a slower drive, nowadays. But, yes, you probably need to get one that was built in the last 5 yrs or so.

TTFN

FAQ731-376

 

[IRstuff]

http://www.magneticsensors.com/datasheets/hmc1001-2&1021-2.pdf

??

TTFN

FAQ731-376

 

[Skogsgurra]

Rhopoint is a supplier with a mature program.

http://www.rhopointcomponents.com/p...SENSORS&subcategory=Linear output GMR sensors

If speed and size isn't an issue, I have used Flux Gates for quite meak magnetic fields. From Wikipedia: "Fluxgate magnetometers are capable of measuring the strength of the magnetic field to about 0.5 to 1.0 nT".

Several suppliers available. Or roll your own.

Gunnar Englund

http://www.gke.org

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