The turbine is patent pending, finally. For this initial test prototype (still maybe 3 years away from production) a short term datalogger would do. We just need to tweak the rotor speed, initially. After that, rotor speed is irrelevant; then the information needed is wind speed to power production. Power output is displayed on most inverters.
Generators can only spin so fast before they go up in smoke.
To give a picture of something not at all like the turbine in question: http://www.mariahpower.com/
but it comes close. I spoke with these people but they either could not or would not tell me what they used to collect their data.
A magnet could be attached to the base and a sensor could pick that up: a bicycle speedometer.
Obviously more data the better.
2 days ago I ordered the Axon. I already have some materials from Parallax. The kid plays with the left overs.
Thanks for your interest.