Description
Overview
The following two models exist:
The models are not interchangeable.
The FL500 UV/IR is optimized for and to be used for hydrocarbon flame detection, whereas the FL500 H2 is optimized for and to be used for hydrogen flame detection.
The FL500 ultraviolet/infrared (UV/IR) flame detector, referred to hereafter as the "FL500" or "device," uses a UV radiation-sensitive phototube and an IR detector to sense specific wavelengths in the UV and IR spectral regions. The UV and IR detectors send signals about changes in the intensity of UV and IR radiation to a microcomputer to activate Alarm Low, Alarm High, and Fault output. A flicker discrimination circuit in the IR circuitry prevents false alarms caused by lightning, arc-welding, hot objects, and other sources of radiation. The inherent flickering of a flame supplies the necessary modulation to activate the IR circuit.
Figure 1 Spectral Response of UV and IR Radiation Detectors
If the device senses only UV radiation (such as arc welding) or only IR radiation (such as a large modulating hot object), an alarm does not occur. If the device senses both UV and IR radiation in the correct combination and intensity, as set by an algorithm in the microcomputer, the device identifies a fire and sends the following output:
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Immediate Alarm Low output |
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Time-delayed Alarm High output |
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RS-485 Modbus RTU output |
The FL500 has the following features:
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Compact unitized design |
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Continuous optical path monitoring (COPM) |
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4 - 20 mA source or sink, alarm relays, and Modbus RTU RS-485 standard |
Figure 2 FL500 UV/IR, FL500-H2 Flame Detector
The FL500 is compatible with the General Monitors TA402A trip amplifier, FL802 controller, and other equipment that accepts 4 - 20 mA output. The device can be connected directly with alarm and suppression devices or switched input modules through integral relays. If the HART protocol is used with the FL802 controller, it is necessary to use the special HART signal (1.25 - 20 mA).
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Because the FL802 controller is not CE marked, it cannot be supplied to the European Union (EU).
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