Non-Linear Potentiometer position calculation

[cstuff]

Can any one help me calculate the position of a gate that
has a non linear Potentiometer. It is a 24" gate When it is open 18" the analog input is reading 3612 when it is open 24" 6816. If the gate is closed the input shows 700

 

[jacekd]

I put your data to Excel. x - analog reading, y - gate position. Made a char out of this data. Added a trend line (2nd order poly) and that's what I got: y = -7E-07x2 + 0,0092x - 6,1082. However it looks like poor fitting.
You could improve it by taking more measurements.

Regards,

Jacek

Do it right or don't do it at all.