- Can be mixed with other detector types on the control panel's initiation detection circuit (IDC)
- Easily maintained; can be cleaned without disassembly
Use the D284 wherever fires can develop quickly. Suitable applications are:
- Petroleum storage areas
- Photographic or film storage areas
- Computer rooms
- Print shops
Warning: The D284 is not a substitute for smoke or heat detectors. It provides an added level of notification for fast flaming fires only.
An ultraviolet-detector tube within the D284 absorbs very weak ultraviolet (UV) light such as that emitted from a flame and produces an electrical current. The detector's electronic circuitry translates this current into an alarm signal. A counter-current prevents alarm signals from single‑pulse UV sources such as lightning or cosmic flares. Additionally, the circuit is tuned to respond only to wavelengths from 185 nm to 300 nm.
The D284's response depends on both the size of the fire and the distance from the fire to the detector; therefore the effective coverage area varies. Very small fires must have a duration of at least 7 sec if within 12 ft (3.7 m) of the detector and a duration of 30 sec if within 12 ft to 25 ft