There's two types of mounted temperature detectors: linear detectors, which watch the temperature throughout a place, and place detectors, which observe the temperature in one certain spot. The PAD200-DUCTR is created and crafted to satisfy all area demands, as well as the NFPA restrictions concerning duct smoke detectors. Air sampling https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/