One can see a number of peaks in both the red (noise) and blue (vibration) data traces in figure 1.

I retrieved the equipment right  after this test (#11, the last test) was completed, around 10:50 on February 2nd. Just prior to picking up the equipment, I was having a coffee at a location by route 22 (Half Day Road) and route 34 (Waukegan Road) when I observed a very long freight train using these railroad tracks. I observed 134 cars being pulled by two diesel-electric locomotives. To show the nature of a freight train passage, I expanded the plot in figure 1 to create the plot seen below: