[Module] Measuring [Type] property [Definition] Relation between a Sensor and a Property that the sensor can observe. Note that, given the DUL modelling of Qualities, a sensor defined with 'observes only Windspeed' technically links the sensor to particular instances of Windspeed, not to the concept itself - OWL can't express concept-concept relations, only individual-individual. The property composition ensures that if an observation is made of a particular quality then one can infer that the sensor observes that quality. [Term Name] 
observes