The IR flame detector model RIV-601P/F is an electronic optical fire detector device that responds immediately to the thermal infrared radiation emitted by fire, and is tuned to the pulse frequency of the flame to ignore sun, lamps and other light and infrared radiation sources.
WHY IR (infrared) FLAME DETECTOR
Eye is faster than nose. In the event of live fire the IR flame detector responds immediately. Its behaviour is similar to that of the eye. In fact it "sees" the radiation emitted by fire, and its sensitivity is inside a cone of 90° which is called the field of view. The minimum flame size that can be detected by the RIV-601P/F varies with the distance. It doubles at double distance and is half at half distance. The sensitivity value is 2-3% of the distance. For example, at 10 m the smallest detectable flame size is 20-30 cm.
WHY IR (infrared) RADIATION
The visible radiation emitted by fire is just a small amount of the emitted energy. The most part is comprised of invisible thermal infrared radiation, typically emitted by all hot bodies, with a wavelength varying with the body temperature. At higher temperature a shorter wavelength is generated and viceversa. The IR flame detector sees very well this IR radiation but is near blind to the visible light. Furthermore the thermal infrared radiation passes through. For this reason the IR flame detector responds to the fire also when smoke is present.
WHY IT DOES NOT RESPOND TO THE SUNLIGHT AND LAMPS
Sun and lamps also generate thermal infrared radiation. But flame is different because it flickers at a particular frequency in the range from 3 to 30 Hz (pulses per second). The IR flame detector is tuned to this pulsing radiation like a radio receiver is tuned to one station and ignores all others. Nevertheless direct exposition to the sunlight and lamps must be avoided, since it causes the detector to become blind or give false alarms.
INFRARED FLAME DETECTOR WATERTIGHT IP66 ENCLOSURE MODEL RIV-601P/F OR EXPLOSION-PROOF ENCLOSURE MODEL RIV-601P/FA
The IR flame detector model RIV-601P/F is an electronic optical fire detecting device which responds immediately to the thermal infrared radiation emitted by fire and is tuned to the flickering frequency of the flame to ignore sun and lamp light.
It is enclosed in a cast aluminum watertight case with IP 66 grade protection, which allows to withstand dusty environment and rain. An IP 66 explosion-proof enclosure is provided for the RIV-601P/FA model.
Nominal 24VDC input power is required, with wide span allowed, and two different outputs are provided: one heavy changeover relay contact, and one NPN transistor open collector.
Both outputs go into alarm state after a pre-set time delay, but they come back to the stand-by state as soon as the fire stops.
The delay time is normally set to 5 seconds, but can be set in the range from 1 to 10 seconds.
A protection against the 24VDC power voltage inversion is provided.
Sensitivity is 2-3% of the distance, that means a 10 cm flame at 5 m distance, or a 20 cm flame at 10 m.
The field of view is a 90°cone, but beyond 90° the detector can see with reduced sensitivity, and can also see behind obstacles due to reflections. A small dust build-up over the detector window does not decrease too much the detector ability, since thermal infrared radiation is little attenuated by dust, much less than light is.
Therefore a frequent window cleaning is not required. Also smoke does not blind the detector, which is operating well with fires in heavy smoke .
It is equipped with the "teletest" device for remote monitoring of detector. This device simulates a flame inside the detector so as to stimulate a sensor response like to a real fire.
The teletest device includes an incandescent bulb and a modulator circuit that generates a pulsating thermal infrared radiation in front of the sensor. The teletest can be manually controlled from a remote site, or it can be automatic and continuously running. The detector response to the teletest is a short alarm pulse of half a second every 4 seconds during all the period the teletest is operated. These short pulses can be recognised by the control panel as a state of live stand-by, since the real fire alarm is continuous. If pulses stop, this means a detector failure or the power voltage is off. A front red LED lamp will signal the detector stand-by or alarm state.
Normally the detector is installed vertically, centered on the area to be covered, so as the 90° cone field of view can be fully used. The ideal height is 0.7 the side of the square area. For instance, if side is 10 m, then height is 7 m and maximum viewing distance is 10 .
If ceiling is lower, corners are the ideal alternative. In this case the height can be one third of the side. Direct viewing of sun and bright lamps must be avoided, since this can blind the detector. In outdoor applications a small hood or roof will help. Vibrating or oscillating mounting must be avoided, since this can be a cause of false alarms .
