Note: This condition may result in noise failures during diagnostics when the AAF of the DAS is set above the natural frequency. AAF settings above 5kHz will result in diagnostic failures. This is an expected condition that is resolved with appropriate post test filtering.
The DTS ARS PRO has a natural frequency between 16-20kHz. This is a frequency component of the internal oscillator that drives the sensors ability to detect changes in rotation.
The 16-20kHz natural frequency is apparent when the data acquisition systems anti-alias filter is greater than the natural frequency. The ARS maximum bandwidth is 2kHz so applying an appropriate software filter below 5Khz will improve the apparent noise performance.
The natural frequency waveform is symetrical. A low-pass hardware or software filter will "smooth" the recorded signal without altering the data within the frequency of interest up to 2kHz.
Images below of ARS PRO data collected at 100k samples/second with a 20kHz anti-alias filter showing FFT, unfiltered data, and with a 5kHz software filter applied