My sensor is way too sensitive - it parks the heads at the slightest movement. I found a way to calibrate it - it did not fix this over-sensitivity, but I thought I'd post this here in case anyone wanted to mess with this tool. http://www.suitable.com/tools/seismacalibrate.html It is free, open-source software. There is an 8 step process. They also have a seismograph app so your lappy can give out earth quake readings.