Position sensing in mechanical systems using Hall-effect magnetic sensors allows precise control while also providing contact free feedback. This increases overall reliability and durability. Since magnetic fields are able to permeate most materials, the sensor can be placed so that it is protected and isolated from other moving parts of the system. This allows for a great deal of flexibility of design. Hall sensors can be used in detecting angular position, angular rotation speed and direction, proximity, and even absolute position. When moving a magnet along a path, some applications require determination of absolute position. This application note covers how to implement this type of design for long stroke movement where it is necessary to use multiple sensors in a linear array.