The Siemens FDO421 Photoelectric Detector in the first place uses state-of-the-art microcontroller circuitry and surface-mount technology for maximum reliability. Model FDO421 incorporates an optical sensor using a light-scattering detection principle. The device utilizes advanced software algorithms to analyze the signals and provides highly stable and accurate smoke detection. Further, Model FDO421 uses state-of-the-art microprocessor circuitry with error check; detector self-diagnostics, and supervision programs. Also, field-Device Programmer Model FDO421 is compatible with the Siemens Fire Safety field-device programmer/test unit (Model DPU), which is a compact, portable, and menu-driven accessory for electronically programming and testing detectors easily and reliably.
The Siemens FDO421 Photoelectric Detector eliminates the need for cumbersome, unreliable mechanical programming methods such as dials or switches and reduces installation and service costs by electronically programming and testing the detector prior to installation.
To clarify FDO421 is a wide-spectrum, photoelectric smoke detector incorporating an infrared light-emitting diode (IR LED), and infrared light-sensing photodiode. In normal conditions, light transmitted by the LED is directed away from the photodiode and scattered through the smoke chamber in a controlled pattern.
in addition, the model FDO421 provides four (4) pre-program parameter sets that can be select by the FACP to match the expected application or environmental conditions: