# Does potentiometer accuracy change with degree of movement?

I want to use a conductive plastic potentiometer for my actuator application where movement is +/- 40 degrees.

As in datasheet, the potentiometer linearity is given as +/-0.2 % which I think is for full rotation. My rotation would be approx 80 degrees only.

Can I say that (80 * 0.2) /100 = 0.16 will be my accuracy for the potentiometer or in every case it will be always (360 *0.2)/100 = 0.7. or what I'm doing is wrong?

Actually, I need a sensor which can give me an accuracy of less than +/-0.2.

• Datasheet link? There are several different ways to specify linearity. But probably it's based on the full electrical travel of the pot, not whatever section of that travel you are choosing to use. Feb 19, 2019 at 11:11
• "...accuracy of less than +/-0.2." Are you going to mount it (mechanically) with the same or higher accuracy?? Or are you going to calibrate it? Feb 19, 2019 at 11:22
• P.S. for accuracy in the range of 0.2 angular degrees you may wish to look at an absolute encoder, and be fairly careful about the mechanical factors. At +/-12 arcminutes you're into a non-trivial area. Feb 19, 2019 at 11:49
• Accuracy and linearity are not the same thing. You should be clear about how the potentiometer is specified and what your actual needs are. Feb 19, 2019 at 12:39