1. Sensor networks: definition and applications

A sensor (figures 1 and 2 ) is a piece of equipment that measures a physical quantity in the surrounding environment, such as temperature, humidity or vibration, and transforms it into a digital quantity that can be processed by computer. A single sensor can be used for local applications.

When equipped with a wireless communication card, the sensor can then be networked, relaying information from other sensors, thus extending their coverage, adding another dimension.