As the demand for increased control and functionality has increased over the years, sensor-instrumented cylinders are becoming more important in the heavy industry, subsea, and mobile equipment worlds. Position feedback sensors for hydraulic or pneumatic cylinders have most commonly used one of three technologies: Magnetostrictive (MLDTs), Variable Resistance (Pots), and Variable Inductance (LVITs) sensors. While other sensor technologies have occasionally been used in this application, the focus of this article is the comparison among these three most popularly used technologies. Ultimately, a user or systems integrator must determine the requirements of the application and which technology best satisfies it on a total installed cost versus performance basis. The strengths and weaknesses of magnetostrictive, variable resistance, and variable inductance sensors are examined below, along with a chart for feature-by-feature comparisons. First, a point to be noted is that all of these three common sensing technologies utilize a long probe that extends into a deep, small diameter blind hole gun-drilled into the internal end of the cylinder rod. Magnetostrictive technology has tra...