Accelerometer How to calibrate the baseline

[Henrik_Volkers]

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@JÞB wrote:

Noise? More likely vibrations.  Sound pressure alone can account for that tenth of a "g".  That's actually, a rather quiet workplace when calculated as 2 to 20 mPa and assuming the sensor itself isn't even a gram of mass.

In  reality an most MEMS accelerometers is are just two capacitors in series sharing a common center plate mounted on a spring and acting as a seismic mass.  Since C=k,the dielectric coefficient,*(area/distance). Since air is easy to come by we use that as a dielectric and k=1.   As the center plate deflects, due to acceleration, the capacitance away from the force increases and the response to the force decreases the distance between the other plates.  The ratio of the total applied voltage and the voltage across either capacitor is nicely linear over Acceleration. 

I only point it out because phyisical environment effects and the simple physics are so commonly overlooked by software developers.  You HAVE TO follow Newton's laws!

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Let's say nearly all accelerometers use a seismic mass (mostly solid, some fluid) and detect the force acting on it.

Just had some MEMS that shift the bias while exposed to (sine) exitation ... good enough for display orientation but useless for inertial measurements 😉  (no , the shaker didn't moved to the sky while calibrating 😄 )

[koukileo]

Sorry everyone, I am preparing to enter the university, preparing for the exam, it may take a while to reply to you all~
Thanks for you all help!!