Android magnetic sensors gives different values of different devices
I am trying to do an analysis which involves interpreting the results from the various sensors of the Android device. Right now I'm analyzing the [magnetic field sensor][1] which should tell me (according to [this documentation page][2]) the values of the ambient magnetic field in uT (micro Tesla). Everything is clear so far but on the 2 devices that I tested on (Galaxy S, Galaxy Gio) the results are different. And by different I mean **very** different.


For example having the same orientation on a table here's what those devices show (just one example):

    S2:  -2,12, 60 (approximate values)
    Gio: -2,12,-36 (approximate values)


Even if I switch positions the results are the same. I also read on [this page][3] about the intensity of the magnetic field and I believe that I should have around 50uT given my geographical latitude.

Can someone explain what those sensors mean? 

Does someone know how to explain this behavior?

Thank you,

Iulian


  [1]: http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_MAGNETIC_FIELD
  [2]: http://developer.android.com/reference/android/hardware/SensorEvent.html
  [3]: http://en.wikipedia.org/wiki/Orders_of_magnitude_%28magnetic_field%29
Android magnetic sensors gives different values of different devices
===

I am trying to do an analysis which involves interpreting the results from the various sensors of the Android device. Right now I'm analyzing the [magnetic field sensor][1] which should tell me (according to [this documentation page][2]) the values of the ambient magnetic field in uT (micro Tesla). Everything is clear so far but on the 2 devices that I tested on (Galaxy S, Galaxy Gio) the results are different. And by different I mean **very** different.


For example having the same orientation on a table here's what those devices show (just one example):

    S2:  -2,12, 60 (approximate values)
    Gio: -2,12,-36 (approximate values)


Even if I switch positions the results are the same. I also read on [this page][3] about the intensity of the magnetic field and I believe that I should have around 50uT given my geographical latitude.

Can someone explain what those sensors mean? 

Does someone know how to explain this behavior?

Thank you,

Iulian


  [1]: http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_MAGNETIC_FIELD
  [2]: http://developer.android.com/reference/android/hardware/SensorEvent.html
  [3]: http://en.wikipedia.org/wiki/Orders_of_magnitude_%28magnetic_field%29