Sensors and Sensing

A sensor is an element that can turn a physical outer stimulus into an output signal, which can then be used for further analysis, management, or making decisions (figure 1). People also use sensors like eyes, ears and skin to gain information about the outer world and act according to their aims and needs. Sensors can be divided into many categories according to the measured parameter of the environment.

Usually, every natural phenomenon – temperature, weight, speed, etc. – needs specially customised sensors that can change phenomena into electric signals, usually the voltage, that microprocessors or other devices could use. Sensors can be divided into many groups according to the physical nature of their operations – touch, light, an electrical characteristic, proximity and distance, angle, environment and other sensors.