TAI Model 6400A SO
4.2 Instrument Description
4.2.1 Sensor Module, Reaction Cell, Detector
The sensor module (Figure 9-7) is where the fluorescence light is generated and detected. It is
the most complicated and critical sub-assembly in the entire analyzer. It consists of the following
assemblies and functions:
1. The reaction cell
2. Reaction cell heater/thermistor
3. PMT and HVPS (high voltage power supply)
4. PMT cooler/cold block/heatsink/fan
5. Preamp assembly:
A. Preamp range control hardware
B. HVPS control
PMT cooler temp control
C. Electric and optic test electronics
Light trap and UV detector
6. UV lamp and light shutter
4.2.2 Pneumatic Sensor Board
The sensor board consists of a pressure sensor and a flow sensor. The pressure sensor measures the
sample pressure at the reaction cell which is near ambient pressure. This sample pressure is
displayed in the test menu. A solid state flow sensor measures the sample flow. Likewise, it is
displayed as a TEST function. The 6400A displays pressure in inches of mercury-absolute (in-Hg-
A) and flow in cc/min.
4.2.3 Computer Hardware and Software
The 6400A Analyzer is operated by an 8088 type micro-computer. The computer's multitasking
operating system allows it to do instrument control, monitor test points, provide analog output and
provide a user interface via the display, keyboard and the RS-232 port. These operations appear to
be happening simultaneously but are actually done sequentially based on a priority queuing system
maintained by the operating system. The jobs are queued for execution only when needed, therefore
the system is very efficient with computer resources.
Analyzer Operator Manual, 02164, Rev. G
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