This is a container for the set of sensors in the system.

A sensor is a physical device whose measurements can be transformed and processed within a given system.

Each sensor is responsible for one measurement signal. Therefore, it measures one quantity and delivers the value by doing so.

The sensor data may be used in the system to perform the joining, but also can deliver other information of the system.

Besides the measured quantity the sensor may expose its calibration information, which may be useful for quality assessment.