Spectrex 20/20L (LB) - UV/IR Flame Detector - Manual (Page 11)

Spectrex Inc. - SharpEye TM UV/IR Flame Detector Manual – TM20/20LB Rev E, August 2004
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2.3 Detection Levels
Simultaneous detection of radiation in both the UV and the IR channels having
an intensity, which exceeds detector’s preset Warning level, will result in a
Warning signal.
In addition, the detector includes an option that detection of UV radiation at high
intensity will result in a Warning Signal.
Simultaneous detection of radiation in both the UV and the IR channels having
an intensity, which exceeds detector’s preset Alarm level, will result in an Alarm
signal.
Simultaneous detection of radiation in both the UV and the IR channels having
an intensity which exceeds detector’s preset Flash-Fire Detection level will result
in an immediate Alarm signal, regardless of the detector mode setting selected.
Since the preset dual range and level of radiation, as well as the flickering
pattern, are characteristic of real fire, all other radiation sources apart from actual
fire will not be detected, thus avoiding false alarms.
2.4 Alarm Signal Delay
The detector is adapted with an Alarm Signal delay selector, allowing the user to
set a different delay between 0 to 30 seconds, mandatory for several specific
applications.
When Alarm level detection conditions are met, an internal time delay is initiated
as preset on the selector. Once the preset time delay has elapsed, detection
conditions are evaluated for 3 seconds. If during that evaluation period Alarm
level detection conditions persist, the Alarm signal is triggered. If no Alarm level
detection conditions endure, the Alarm signal Delay is reset.
2.5 Built-In-Test (BIT) Capabilities
The detector (only 20/20LB) is adapted with Built-In-Test (BIT) capabilities. The
BIT is continuously performs at predetermined time intervals averaging 60
minutes. It performs automatic full-featured test of the detector’s internal electric
circuits, and checks the radiation sensors and the detector window’s cleanliness.
The BIT circuits will generate response signals to indicate satisfactory operation
of the detector or a fault should it be detected during a BIT sequence. The BIT
sequence can also be initiated manually by the user at his preference, upon a
remote operation from a control unit.