i wan't to measure linear distance with linear resistance and carbon type resistance

 

What range of distances are you trying to measure?

 

Given the particulate nature of carbon I'd be surprised if you could get 2 micron accuracy from a carbon resistance track.

 

You could conceivably gear up the movement so the track sees a greater movement distance.

 

Is it necessary to use resistance as a measurement basis?
The device shown here has the required measurement accuracy, if it could somehow be adapted:
LVDT instrument
They are commercially available.

 

Hi,

Carbon also wears out.