Taylor Mackinnon put a temperature/humidity unit on his dinning room table and a sending unit in the piano in the living room with the Music Sorb.  Then he has recorded the data each morning when he gets up and in the evening as well.  The two top lines are temperature readings, the orange is in the room, the red is in the piano next to the Music Sorb.  The two bottom lines are humidity readings light blue is in the room and the dark blue is next to the Music Sorb in the piano.  Those of you who know what the weather is like in the Willamette Valley in Oregon will understand the relatively consistent readings through-out the year.  Still, there is quite enough humidity fluctuation to affect a change in the tuning of a piano.