ADXL355 for Seismometer

Thank you for posting your question in this forum and for your support of Analog Devices.  We certainly appreciate your partnership and will be happy to help you evaluate these requirements. 

If we assume a single-pole filter, with a cut-off frequency of 200Hz, we can predict the total noise to be: 

Noise = 20ug/sqrt(Hz) x (sqrt(1.6*200)) = 357ug (rms) = 0.357mg (rms)

This means that it would be tough to support an absolute accuracy of +/-0.5mg, but it seems like this would enable detection of +/-0.5mg of motion.  Does that help? 

Hi 

Thank you for your reply.

Do you know if ADXL355 Noise(0.357mg) can be removed with a processor and a filter?

Could you introduce the other accelerometer?

Best regards

N.Kokubo

Do you know if ADXL355 Noise(0.357mg) can be removed with a processor and a filter?

• NevadaMark: Not that I am aware of. The key trade space is between bandwidth and noise. 

Could you introduce the other accelerometer?

• NevadaMark: The ADXL355 is presently our lowest noise accelerometer.  

Hi

Thank you for your answer.

I close this question.

Best regards

N.Kokubo

Hi

Thank you for your answer.

I close this question.

Best regards

N.Kokubo

Why 200Hz bandwidth ? do you mean sampling rate ?

ADXL355 has predefined 125 and 250 samples per second, with LPF (bandwidth) = 31.25 and 62.5 Hz respectively.

With 125 samples per second I get RMS = 0.09 mg.