What's the best way to measure very small mechanical movements very accurately?
I'd like to make an instrument to measure the angle of attack that a planes wing makes with the air. Mechanically it's very simple, I attach a freely rotating vane to the front of the aircraft and measure the angle this vanes makes relative to the airflow.
relative to the airframe, surely?
Option three - same as option two but using hall switches instead. Disadvantages - all the same disadvantages as for option 2, and costs a lot more.
No, not hall switches, a linear hall sensor (analog output). Arrange the range of movement to bring the magnet
pole from one side of the hall sensor to the other and the detected field strength will have a good range of values.
Calibrate by hand (be prepared to reposition the sensor a bit to get a good response curve).
You'll only need a very small neodymium magnet so very little weight. If you can arrange the magnet to counter
balance the vane's weight even better.