I am writing an application for WP7 utilizing the compass sensor. And there is a problem with the raw magnetometer reading vector. In HTC I get such a vector that when taken its length I get magnetic field intensity in micro Teslas. Recently I have got a Nokia Lumia 800 and it shows the magnetometer readings vector as a scaled vector with values from -1 to +1.
The question is how it is scaled or how to make it working as it is in HTC?