R2 sensor array

An R2 sensor array, also known as a Scan-mode sensor, was a scanner array that was standard for Industrial Automaton's R2-series astromech droid. The device could monitor radiation levels and detect nearby lifeforms. The scanner rose out of a droid's dome on a hydraulic extension with a reinforced metal rod. At the top was a signal amplifier with a two small lights and square, curved lifeform scanner comprised of life-scan mesh. A cable at the bottom of the rod served as the main logic processor connection.

R2-D2 had one of the scanners which he used at various times, including while searching for signs of Luke Skywalker when the Rebel was lost on Hoth shortly before the Battle of Hoth.

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