Chemical identity sensors
Chemical identity sensors were a part of the sensor system found aboard  starships, used in identifying chemicals.

While scanning an unidentified cosmic cloud in the Pallas 14 system, Spock began getting unusual readings on it from the chemical identity sensors. These sensors reported elements within the cloud that were unknown in Federation periodic tables, helping him determine that the cloud was of extragalactic origin. ()

Sensor technology

nl:Chemische identiteitssensoren