sen·sor 
/ˈsɛnˌsoɚ, ˈsɛnsɚ/ noun
plural sen·sors /ˈsɛnˌsoɚ, ˈsɛnsɚ/ noun [count] : a device that detects or senses heat, light, sound, motion, etc., and then reacts to it in a particular way
▪ a motion/optical sensor ▪ Image sensors are used in digital cameras. ▪ Infrared sensors can track an object's movement.
▪ a motion/optical sensor ▪ Image sensors are used in digital cameras. ▪ Infrared sensors can track an object's movement.
