I am a visual person and I need to see things to understand them, so I made these graphs:
Stretched to 125 % of original length.
Stretched to 150 %
Stretched to 175 %
Stretched to 112.5 %, 125 %, 137.5 %, 150 %, 162,5 %, and 175%
Stretched with incrementions of 6.25 %
Due to the fact that I am lazy the graphs might be a bit confusing to read. The x-axis represents time and the white vertical lines
represent seconds (I just double checked my math and the white lines are more like half seconds - maybe I will redo these if I get around to it. However you still get the generally picture). The y-axis measure the change in resistance. The light gray area is the resistance of the sensor. I did not add units, as the interesting part is the relative change and that is all I measured.
The fact that the signal is non-linear can, with some tinkering, be used as a bonus. The resolution in the first couple percent of stretch is quite high - so if I where to use two stretch sensors simultaneously but in opposite phase (if one is loose, the other one is stretched) I should be able to maximize the resolution available :-)