Re: need a help to find a sensor to measure Linear displacem
If the meter can contact the blades, you could use a digital micrometer (about $25.), which is able to read linear displacement, mechanicaly. They have a range of about 4 inches, can read out inches or mm, and have the resolution you specify. If no contact is allowed, but a reflector can be attached, you could use an optical interferometer, which has resolution of less than a micron. Or use a capacitive proximity sensor, which may be able to resolute at your spec. Depends on your budget and specifics of your application. Try googleing the one above that could work for your specs. Pat