What is a Potentiometric Ruler?

A Potentiometric Ruler (or Linear Potentiometer) is a simple, cost-effective sensor used to measure position or displacement. It works as a variable resistor.

Working Principle

It contains a resistive track and a wiper (slider) that moves along the track. As the wiper moves, the resistance between the wiper and the end of the track changes linearly.

By applying a fixed voltage (e.g., 10V) across the track, the voltage at the wiper becomes directly proportional to the position.

Comparison vs LVDT

Pros: Cheaper, simpler electronics (DC voltage output), absolute position (no homing needed).
Cons: Physical contact causes wear over time (limited life cycles).

These sensors are widely used in injection molding machines, hydraulic presses, and general automation, often read by devices like the GDT Digital Transmitter.