The S512 viewing head incorporates a PbS photo detector which has a
spectral response that ranges from 1000-3000 nm (nanometers). It will detect
all types of flames including natural gas and propane. It has nearly identical
characteristics to the S509 with its Si detector turned off. It utilizes a Si
filter which blocks all radiation above 1000nm (visible range and new
infrared). In this respect it is identical to the PbS detector used in S509.
However, an AR (anti-reflective) coating is used over the Si filter which
prevents the longer wavelengths from being reflected resulting in a signal
level about 2X greater that the S509 (with Si channel off).
The signal from the detector is a flicker signal. All flames pulsate
creating a flicker component which is what the S511 detects. The flicker
frequencies emitted from flames range 0-2000Hz. The S512 responds to only the
higher frequencies while rejecting the lower frequencies which are part of the
general furnace or background flames.
The S512 with its PbS photo detector has a linear response from low to
medium brightness flames, that is, no distortion of flame signal occurs with
regard to any amplifier saturation or AGC action (compression), However,
saturation will occur with the PbS element on bright flame. This condition can
easily be rectified by using orificing (placing disk with small aperture in
front of lens to reduce the amount of light or radiation).
The S512 employs electronics self-checking which is implemented by using an
electronic switch that disconnects the photo detectors every second for 200
milliseconds. The resulting chopped signal is fed to the signal processor
which monitors the signal in a fail-safe manner.
The S512 is a bonafide infrared flame monitor (not to confused with the Si
detector which are really visible light detectors). The S512 is particularly
useful for multi-burner oil and coal fired boilers where discrimination is
Please call or email for pricing and availability at 281-421-1321 or email@example.com.