Sensors

         Ultrasonic sensors detect the position of objects with a sound-reflecting surface. They may be used at an operating distance of up to 6 meters

         Photoelectric Sensors "see" light-reflecting or opaque objects at an operating distance of 5 meters and more. They can also be used with fiber-optic cable for detection of extremely small objects.

      Proximity Sensors :There are two types Inductive and Capacitive. Inductive sensors detect metallic objects at an operating distance of up to 50mm. 
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Sensors