Figure 10-9: Gfc Light Mask; Figure 10-10: Segment Sensor And M/R Sensor Output - Teledyne 300E Instruction Manual

THEORY OF OPERATION
KEY:
M/R Sensor
The emitter/detector assembly that produces this signal 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.
Segment Sensor
This emitter/detector shines through a portion of the mask that is divided into the
same number of segments as the portion of the mask through which the IR beam
passes. 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.

Figure 10-10: Segment Sensor and M/R Sensor Output

168
Detection Beam shining
through MEASUREMENT
side of GFC Wheel
Detection Beam shining
through REFERENCE
side of GFC Wheel
IR Detection Ring
Segment Sensor Ring
M/R Sensor Ring

Figure 10-9: GFC Light Mask

Model 300E Carbon Monoxide Analyzer
Measurement
Pulses
Reference
Pulses
Instruction Manual
IR Beam
Pulses
Segment Sensor
Pulses
MR Sensor
Pulses
P/N 04288 Rev: A