The temporary T240 as ground sensor for ETMX SEI sensor correction was swapped on Tuesday 7 July with an STS2. Attached are spectra comparing the signals. Obviously we can't compare signals at the same time so the T240 time is 3 July at 0200 local and the STS2 time is 9 July at 0200. Based on the wind trends, these are pretty quiet times for wind.
To assess the stationarity of the Spectra, I walked before and after this time a few hours on July 3 and the variability below a Hz can be many factors. With the 0200 July 3 signals as reference, I walked before and after 0200 on 9 July and really found no close match, again especially at lower frequencies. The Z DOF of the T240 below about 30mHz seems to be main outlier but above about 200 mHz the traces are maybe within a factor mostly. There is an exception to that centered around 0.6Hz with the T240 showing a bit higher amplitude especially on the Y DOF. Maybe we could argue that our calibrations for these two instruments are correct.