title: Android magnetic sensors gives different values of different devices
body: <p>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 <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_MAGNETIC_FIELD" rel="nofollow">magnetic field sensor</a> which should tell me (according to <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html" rel="nofollow">this documentation page</a>) 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 <strong>very</strong> different.</p>
  
  <p>For example having the same orientation on a table here's what those devices show (just one example):</p>
  
  <pre><code>S2:  -2,12, 60 (approximate values on x,y,z accordingly)
  Gio: -2,12,-36 (approximate values on x,y,z accordingly)
  </code></pre>
  
  <p>Even if I switch positions the results are the same. I also read on <a href="http://en.wikipedia.org/wiki/Orders_of_magnitude_%28magnetic_field%29" rel="nofollow">this page</a> about the intensity of the magnetic field and I believe that I should have around 50uT given my geographical latitude.</p>
  
  <p>Can someone explain what those sensors mean? </p>
  
  <p>Does someone know how to explain this behavior?</p>
  
  <p>Thank you,</p>
  
  <p>Iulian</p>