2.4.2. "Sensor" Concept

The "sensor" concept is an essential element of the IRRHEM ontology; it detects the information coming from the physical environment and reacts to it. The information captured can be light, heat, movement, humidity, pressure, or other environmental phenomena (Figure 4). The output is typically a signal that is converted to an operator-readable display at the location of the sensor, or transmitted electronically over a network for reading or processing.

**Figure 3.** Impact of the introduction of the "Call" concept in IRRHEM.
