DETECTOR SMOKE OPTICAL

Orbis Marine Optical Smoke Detector

òPhotoelectric Smoke Detector
òMarine Approved
òConventional Type
òFor Non-Hazardous Applications

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Features and Benefits

òFor general use; marine approved Optical Smoke Detector
òSuitable for smouldering fires and escape routes
òDesigned to reduce significantly the incidence of false alarms through over-sensitivity to transient phenomena
òImproved sensitivity to black smoke
òCompensation for slow changes in sensitivity
òExtra confirmation of smoke before the alarm signal given
òAvailable as standard or with flashing LED
Product Summary


A conventional optical smoke detector approved for Marine use. The performance of Orbis Marine optical detectors is good in black as well as white smoke. In this respect Orbis is different from traditional optical smoke detectors which perform far better in white smoke than in black. Orbis optical detectors are recommended for use as a general purpose smoke detectors for early warning of fire in most areas.
Operating Principles



Optical Smoke Detectors have always been recognised as good detectors for general use. They are regarded as particularly suitable for smouldering fires and escape routes.

The performance of Orbis Marine optical detectors is good in black as well as in white smoke. In this respect Orb is is different from traditional optical smoke detectors which perform far better in white smoke than in black.

Orbis Marine optical detectors are also designed to reduce significantly the incidence of fa lse alarms through oversensitivity to transient phenomena.

Orbis optical detectors are recommended for use as general purpose smoke detectors for early warning of fire in most areas.
Orbis Marine Optical Smoke Detector



The sensing technology in the Orbis Marine optical smoke detector is significantly different in design from previous optical detectors. A full description is given in the section æHow do Orbis Marine optical smoke detectors work?Æ but the advantages of this system and its associated algorithms are:
òimproved sensitivity to black smoke
òcompensation for slow changes in sensitivity
òextra confirmation of smoke before the alarm signal given

The algorithms are used to verify signals from the sensing chamber; to filter out transients and to decide when the detector should change to the alarm state.

All this combines to increase detection reliability and reduce false alarms.
How does the Orbis Marine Optical detector work?



Orbis operates on the wel l established light scatter principle. The remarkable optical design of the Orbis Marine optical smoke detector allows it to respond to a wide spectrum of fires.

The sensing chamber contains an optical sensor which measures back-scattered light as well as the more usual forward-scattered light. Sensitivity to black smoke is greatly
improved.

The detector is calibrated so that Orbis is highly reliable in detecting fires but is much less likely to generate false alarms than earlier smoke detectors.

The stability of the detector- high reliability; low false alarm rate- is further increased by the use of algorithms to decide when the detector should change to the alarm state. This
removes the likelihood of a detector producing an alarm as a result of smoke from smoking materia ls or from another non-fire source.
Technical Specifications and Ordering Information



Technical Specifications



Technical Data:

Specifications are typical at 24V; 23¦C and 50% relative humidity unless otherwise stated.



Principle of Detection:

Photoelectric detection of light scattered by smoke particles over a wide range of angles. The optical arrangement comprises an infra-red emitter with a prism and a photo-diode at 90¦ to the light beam with a wide field of view. The detectorÆs microprocessor uses algorithms to process the sensor readings.



Sampling Frequency:

Once every 4 seconds



Supply Voltage:

8.5-33VDC



Supply Wiring:

2 wires; polarity sensitive



Maximum Polarity Reversal:

200ms



Power-up Time:

<20 seconds



Minimum ædetector activeÆ voltage:

6 V



Switch-on surge current at 24V:

95¦A



Alarm Current:

At 12 V 20mA | at 24V 40mA



Alarm Load:

600 ohms



Holding Voltage:

5-33V



Minimum holding current:

8mA



Minimum voltage to light alarm LED:

5V



Alarm reset voltage:

<1V



Alarm reset time:

1 second



Remote output LED (-) characteristic:

1.2k ohms connected to negative supply



Material:

Detector and base moulded in white polycarbonate



Alarm indicator:

Integral indicator with 360¦ visibility



Dimensions and weight:

97 mm diameter x 31 mm
Weight; 75g
(In base) 100 mm diameter x 46mm
Weight; 135g



Temperature:

Operating and storage
-40¦C to +70¦C
(no condensation or icing)



Humidity:

0% to 98% relative humidity (no condensation)



Wind speed:

Unaffected by wind



IP rating to EN60529:

23D


Specifications subject to change without notice.