Electrical Noise of Accelerometers

Each accelerometer has some inherent noise that can mask real vibration levels if the noise exceeds those levels. This article provides a bit more detail as to the characteristics of our accelerometer noise.

Tutorial Video

The following is a bar chart comparing the RMS noise levels of a typical accelerometer. There will be some variation unit-to-unit. Also the noise level will scale linearly with the measurement range. For example, a 100g piezoelectric will have 4x the noise levels as the 25g piezoelectric. A D8 will have 1/5x the noise compared to the D40.

PSD of Noise

Here is an interactive power spectral density of the noise floor of each accelerometer. Again, these will scale linearly with the measurement range. Note that the piezoresistive accelerometers have periodic noise at around 25 Hz that is the update frequency for temperature correction within the on-board programmable gate array. It’s a characteristic of the device.

For printing purposes, here is a static image of this same PSD.

Python Reference Code

This PSD and RMS plot was generated with native Python code that utilizes the endaq open-source Python library. To see the code, visit this colab notebook.