how linear is a linear potmeter

wha?? Potentiometer.

You'll probably have to measure that. I suspect pots are all different.

Should be in the specs. Somewhere between 20% and 0.2% is common, depending on the type of pot and the intended purpose. Best situation typically is to avoid the bottom and top electrical 5-10% of the pot. Usually the mechanical motion (to the end stops) goes well beyond the electrical range (ie. the angle to go from 5% to 95% of the resistance is much less than 90% of the angle between the end stops).

You'll also get better results by using the potentiometer as a potentiometer rather than a rheostat, with little current flowing through the wiper.

Ten turn pots are usually rated for a few percent linearity. Your average carbon track type, who knows.

Tim

-- Deep Friar: a very philosophical monk. Website:

You need to look that information up the venders web page.

It varies depending on how much you want to pay!

average=20

They were a darn sight better than that back when they were popular, say = about 0.10% linearity. Or go find a current data sheet.