Teledyne GFC-7001T - Trace CO Analyzer - Manual (Page 301)

Theory of Operation Teledyne API – Model T300/T300M CO Analyzer
Teledyne Analytical Instruments 301
other photo emitters/detectors. These devices consist of a combination LED and
detector mounted so that the light emitted by the LED shines through the same mask on
the GFC Wheel that chops the IR beam.
IR Detection Ring
Segment Sensor Ring
M/R Sensor Ring
KEY:
Detection Beam shining
through MEASUREMENT
side of GFC Wheel
Detection Beam shining
through REFERENCE side
of GFC Wheel
Figure 13-11: GFC Light Mask
M/R S ENSOR
This emitter/detector assembly produces a signal that shines through a portion of the
mask that allows light to pass for half of a full revolution of the wheel. The resulting
light signal tells the analyzer whether the IR beam is shining through the measurement
or the reference side of the GFC Wheel.
S EGMENT S ENSOR
Light from this emitter/detector pair shines through a portion of the mask that is divided
into the same number of segments as the IR detector ring. It is used by the
synchronous/demodulation circuitry of the analyzer to latch onto the most stable part of
each measurement and reference IR pulse.