Fire Projects recommend Models FSV-951R and FSV-951R-IV are plug-in type smoke sensors that combine a photoelectronic sensing chamber with addressable-analog communications providing sensitivities from 0.02% per foot to 2% per foot obscuration for Early Warning Fire Detection (EWFD) or Very Early Warning Fire Detection (VEWFD).

The sensors transmit an analog representation of smoke density over a communication line to a control panel. Rotary dial switches are provided for setting the sensor’s address. Two LEDs on the sensor are controlled by the panel to indicate sensor status. An output is provided for connection to an optional remote LED annunciator.

Notifier panels offer different features sets across different models. As a result, certain features of the photoelectric sensors may be available on some control panels, but not on others. FSV-951R will support only FlashScan® protocol mode. FSV-951R-IV will support either FlashScan or CLIP (Classic Loop Interface Protocol) mode.