Typical GE and Westinghouse Steam Turbine Control Valve System Position Sensors (LVRT and LVDT) Installation Locations in US Fossil Fuel Fired Power Generation Plants. Macro Sensors Part Numbers. 

The letters LVDT are an acronym for Linear Variable Differential Transformer, a common type of electromechanical transducer that can convert the rectilinear motion of an object to which it is coupled mechanically into a corresponding electrical signal. LVDT linear position sensors are readily available that can measure movements as small as a few millionths of an inch up to several inches, but are also capable of measuring positions up to ±20 inches (±0.5 m).