Suggestion, I am not a expert in electrical, my background is mostly automotive electrical.When I measure pots, I use a old analog multimeter, the type with a needle. I run pot through it's travel range and watch the needle for smooth sweep in the range specific to the pot. With a digital you can't see drop outs because the digital display changes so fast you can't see it. I would guess it could probably be done with a scope also, but old-timers like myself are more likely to have a old analog multimeter laying around. Hope I am not steering anyone the wrong direction.