There's two kinds of preset temperature detectors: linear detectors, which check the temperature all over a place, and location detectors, which monitor the temperature in one precise location. The PAD200-DUCTR is intended and crafted to fulfill all community necessities, together with the NFPA restrictions with regards to duct smoke detectors. https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/