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The flame detectors are used for the supervision of
gas flames, yellow- or blue-burning oil flames and for ignition
spark proving. High sensitivity.
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With this type of flame supervision, the UV radiation
emitted by gas or oil flames is used to generate the flame
signal.
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The radiation detector consists of a UV-sensitive
cell with 2 electrodes, which ignite when illuminated with
radiation in the 190...270 nm range of the spectrum, thereby
triggering a current in the flame detector circuit.
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The UV cell does not respond to glowing firebrick in
the combustion chamber, daylight or light from the boiler room
illumination.
The die-cast alloy flame detector head is sealed with
a quartz-glass lens. In addition to the plug-in UV cell, the head
contains a rotating shutter which – for the purpose of continuous
testing of the UV cell’s striking and extinction voltage
performance – interrupts the UV radiation at the rate of 3 times
per second. The shutter is driven by a synchronous motor which is
suited for continuous operation.
The flame detector is attached to the viewing tube by
means of a flanged mounting coupling which has a 1 in. internal
thread. A 3/8 in. tapping on the side of the coupling enables a
cooling air conduit to be connected, provided that dry, dust- and
oil-free compressed air is available.
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