I am using a MPU 9250 (three axis accelerometer) with an ESP 8266 to perform vibration monitoring on machine.
I am trying to compare vibration results between the Mems (MPU9250) and a PCB ICP piezo accelerometer (model 352C33), but I am finding some divergences, such as max, min and rms acceleration amplitude.
Follow attached one image from the measurement I performed on a industrial machines: (attachement Capturar.PNG)
Note that I am getting +/-50% less amplitude with the Mems sensor, and I can't understand why...
Even when I perform simple test with sinusoidal signal, there are amplitude differences: (attachement Capturar 2.PNG)
I already performed a test with the sensor stopped on the table, and it's delivering 0g in X and Y direction and 1g in the Z direction (vertical). Do you have any idea of what can be my problem?
Is MPU9250 a good sensor for this purpose?