A convenient way of applying a magnetic field is a pair of Helmholtz coils.
The magnetic field is a function of current through the coils.
I used this method for my dissertation to test a similar-size chip
containing a magnetic-field sensor. See
http://www-bsac.eecs.berkeley.edu/archive/kirt_williams_phd.zip , Chapter
11, pp. 293-295.
This will work across temperature and in liquids (be sure to insulate if the
liquid is conducting).

Something to be aware of is that the setup will apply an electric field as
well as the magnetic field.
You can check you sensor for sensitivity to electric fields alone by only
connecting one end of the coils to a voltage source, with ground connected
to the chip substrate or package.

    --Kirt Williams

----- Original Message -----
From: "Imran Ghauri" 
To: 
Sent: Wednesday, September 14, 2005 8:36 AM
Subject: [mems-talk] Temperature sensing in magentic fields !!!


> Hi all,
>
> We've fabricated some thin film Cu RTD (resistance temperature detectors).
We want to test them in magnetic fields and in some fluids. Can someone give
some suggestions about how to create the magnetic field around the RTD. We
also want to monitor the magnetic field strength, and if it can be varied
then it will be great. The chip size of RTD is 7mmx7mm. The substrate
material is Silicon.
> Any suggestions under fluid conditions would also be appreciable.