(Newb) Measuring Force

Hi I want to measure force using an Arduino Duemilanove. Right now I'm looking at a few piezoresistors, thinking to wire them to the ADC. Any considerations I should keep in mind? Are there other more practical/accurate solutions around?

Thanks for the help

It very much depends on the application. Load cells such as used in digital scales and digital kitchen scales are one route, and there's even a way of using a vibrating wire's resonant frequency to measure its tension. A pressure guage can measure the force applied to a piston of known area too. Another approach is to use a motor or actuator to resist the force - use position feedback to keep the motor stationary and the current it takes will be proportional (in principle) to that force - you might even be able to do this with a standard servo and a current-sensor.

How much force? Can the sensor be compliant (move, with more force causing more displacement), or does it need to have very little movement with applied force?

Well, I'm actually trying to measure how much force I can get from servos for a plane I'm building. Under the current setup, the plane's tail will hit the piezoresistor vertically, and this in turn goes to the adc since I want to log all the information. My first thought was to go with the piezo right away, but now I will research everything you mentioned, Mark.

Terry, the servos output around 6 kg*cm. Like I said, since I'm just starting the research in order to build the test stand, pretty much everything goes.