San Bergmans wrote:
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An accelerometer can show the rate of tilt. The more you point the sensitive axis towards the ground, the more it is affected by the accelaration of the the earth's gravity (which is 1g).


Nope, an accelerometer is a FORCE sensor, which has a mass (often called the SEISMIC) mass attached to it. At zero acceleration, there is zero force, at a high acceleration, there is a high force on the mass, which is measured. The trick with accerometers is the art of making them insenstive to movements of the seismic mass out of the plane of the transducer. A potential for acceleration does not cause an indication on an accelerometer unless it is measuring exactly what it shouldn't, the static forces on the mass. Accelerometer manufacturers go to great lengths to make damned sure they aren't sensitive.

Steve