High accuracy with ST industrial accelerometers?

[PDegt.1]

Is it possible to achieve 0.05 degree angle measurement accuracy with ST accelerometers? If yes, which one would be recommended for static measurements 0-90 degrees?

[Eleon BORLINI]

Hi @PDegt.1​ ,

I would suggest you to use one of the accelerometer dedicated to the inclinometer funcition, such as for example the IIS3DHHC. This is a high-resolution, high-stability 3-axis digital accelerometer for tilt measures.

Using the formula in application note AN5146 p.19, you can calculate the tilt angle knowing the 3 components of the acceleration:

The best-sensitivity case for the single axis case is the 45° position, as described in the application note AN4509. But considering for simplicity the flat position case, the sensitivity along x and y is 0.076 mg/digit (datasheet p.), while you have 1 along z. From the equation, you get r = arctan(0.076*10-3) that is less than 0.01degree.

Of course, this is the ideal case, and you should take into account all the deviations from linearity, but you should control them (at least partially) making appropriate averaging of the signal.

-Eleon