Table 3 Sensors’ classification

This refers to sensors that gather data from the environment or the space around them.

This is used to perceive motion of people or things in a context (as in accelerometers and gyroscopes).

This category holds the sensors that are applied to electricity grids.

The biosensors are worn by humans or animals. They return vital signs and/or biological information about one subject.

This represents a semantic or identity of another thing to the IoT system. The most common items in this classification are RFID and NFC tags and their readers.

This is related to identifying an object’s position in a global scale (as with GPS) or in a local scale (as in small beacon position).

This captures the presence of a person, an animal, or object in a space and registers it in the system. The most common solution is the PIR sensor.

This family of sensors captures images that will be processed by a computer to produce information.

These types of sensors are devices that are human-activated to trigger an event, such as a button or a lever.

Such sensors are activated by soundwaves, producing data from the ambient sound change.

The force/load sensors are activated by external forces, capturing the deformation or the intensity of those forces to the system.

These are applied in the water system to measure and control the flow.

Chemical sensors are capable of detecting chemical substance(s) in the air or water.

This specific category includes sensors with similar functions to the previous categories. They differ in that their application is confined to a specific object. The object information is the result of a small context application of a sensor. For instance, a temperature sensor used inside a machine provides object information which is different from an ambient temperature sensor.