Abstract: A high resolution, high reliability, magnetically coupled, linear position sensor (50) provides a means of determining the position of an object (51) using a methodology that does not require a direct mechanical or physical connection between the sensor (50) and the object (53) whose position is to be determined. The sensor (50) can operate in a high temperature, high pressure fluid with exposure to moderate levels of radioactivity. The sensor (50) utilizes dual rod elements with a magnetically coupled bridging contact slider (51) supported by a ceramic guide all of which are contained within a non magnetic pressure housing. The topology of the sensor (50) supports at least two types of measurement techniques, Time Domain Reflectometry (TDR) as well as linear resistive to determine target (51) position.