anyone know of a low friction potentiometer?

[deckerscott]

Hi there,
im new here so excuse me if this sounds a bit simple, i would like to measure how much water is in a small tank. I thought i could go about it in the same way a fuel gauge works, basically a float attached to an arm which is attached to a potentiometer. When the float moves up and down the potentiometer will turn and then i can read the different outputs and therefore know how much water is in my tank. The problem is that the potentiometers i have available are fairly hard to turn which means that the float will not be enough to overcome the friction. Does anyone know of a low friction potentiometer which could work or if you have any suggestions on how else i could do this that would be greatly appreciated,

thanks for your time,

Scott

 

[Willbe]

Does anyone know of a low friction potentiometer which could work or if you have any suggestions on how else i could do this that would be greatly appreciated,

thanks for your time,

Scott

The car manufacturers have solved this problem with their fuel tank sending units, probably by using leverage.
Another way is an LVDT but the circuitry is more complicated. Or an optical decoder.

 

[user_88]

There is a special potentiometer that is used as a sensor, it is generally a low friction type, with a full range extending or encompassing one revolution .... 2*pi radians.

You should be able to obtain a usable voltage range with such an item.
I'm not sure about the moisture or humidity limitations....

Take a look at this page:
Single turn, conductive plastic potentiometers -Precision Sales Inc.-The Potentiometer Specialists™

The cost will probably be greater that an ordinary potentiometer.

 

[Mike_2545]

Waterproof potentiometer

Here is an interesting item SparkFun Electronics - MagnetoPot - Waterproof Potentiometer

A magnet in a contact-less connection will sense the level with this.

Should be-zero friction-