Teledyne T803 12.4. PNEUMATIC OPERATION

Teledyne API T803 CO2/O2 Analyzer Operation Manual Principles of Operation
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12.4. PNEUMATIC OPERATION
CAUTION
GENERAL SAFETY HAZARD
IT IS IMPORTANT THAT THE SAMPLE AIRFLOW SYSTEM IS BOTH LEAK-TIGHT AND NOT
PRESSURIZED OVER AMBIENT PRESSURE.
Regular leak checks should be performed on the analyzer as described in the maintenance
schedule, 10.1.
Procedures for correctly performing leak checks can be found in Section 10.3.3
In pneumatic operation an internal pump creates a vacuum that draws sample gas
into the analyzer. Normally the analyzer is operated with its inlet near ambient
pressure either because the sample is directly drawn at the inlet or a small vent is
installed at the inlet when the sample is delivered under pressure. There are
several advantages to this “pull through” configuration.
 First the pumping process heats and compresses the sample complicating
the measurement process. Both heat and pressure affect the accuracy of
gas measurements.
 Additionally, certain physical parts of the pump itself are made of materials
that might chemically react with the sample gas.
Figure 12-5: Internal Pneumatic Flow
07276B DCN6418