How can I select the right Accelerometer?

[JAmuc.1474]

I am designing a sensor to measure vibration from industrial equipment.

The main characteristics of the accelerometer are listed below:

- Acceleration Range - up to 8g

- Type - Digital

- Output Type - I²C, SPI

- Axis - X / Y / Z

- Bandwidth - minimum of 1.6KHz (as higher the better)

- Resolution - 16 bits

I found a lot of accelerometer that meet the specifications above, although I am not being able to understand how can I guarantee a good resolution in high frequencies of the accelerometer.

I already tested the MPU9250 in a shaker and the results in low frequency (until 150Hz) is reasonable, although in high frequencies (from 150Hz until 1kHz) it is horrible as shown below:

ps- the blue dots are the reference accelerometer (piezoeletric) and the orange dot is the MPU9250.

My question is:

-       How can I understand from the datasheet that the resolution in high frequency will be ok?

[Ozone]

> -       How can I understand from the datasheet that the resolution in high frequency will be ok?

Checking for frequency response parameters in the datasheet ?

The curve looks strange. There seems some resonance involved.

Unless you provide a reference signal (known acceleration), you cannot say which sensor is more off.

[JAmuc.1474]

I tend to agree with your statement, althought there are some reasons why I believe in results above:

• The test was performed several times and the results were all the same
• I used more than one piezoeletric accelerometer to double check the results, and I got the same thing