Figure 8-1. Hardware Components; Optical Bench - Thermo Scientific 48i Instruction Manual

System Description
Hardware
Flow Transducer
Fan

Optical Bench

Scrubber
Front Panel
Front Panel Board
Optical Bench
Band-pass Filter
Bench Heater Board
Chopper Motor
8-2 Model 48i Trace Level-Enhanced Instruction Manual
Pressure Transducer
Transformer
Power Supply
Measurement Interface Board
Figure 8–1. Hardware Components
The optical bench is an airtight chamber that contains the sample gas. The
bench includes mirrors that cause the infrared light from the infrared
source to pass through the sample gas multiple times before reaching the
infrared detector.
The band-pass filter limits the light entering the optical bench to a narrow
band of the infrared portion of the spectrum.
The bench heater board applies power to the bench heater resistors and
transmits the bench temperature monitored by a thermistor. This assembly
is used for maintaining the optical bench at a constant temperature.
The chopper motor spins the gas filter wheel and chopper disk at a uniform
speed.
Pump
Thermistor
Motor and Wheel Assy
Fan
Span
IR Source Cover
Detector Assy
and Pre-Amp
Sample/Zero
I/O Expansion Board (Opt)
Digital Output Board
Motherboard
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