Teledyne 7320 - NDIR analyzer - Manual (Page 74)

5 Maintenance Model 7320
5-2
Teledyne Analytical Instruments
5.1 Routine Maintenance
The 7320 should be inspected on a regular schedule to be determined
by the maintenance personnel. The system filter and analyzer
measurement cell should be maintained as required by the quality
of the sample.
Periodic calibration of the system will assure accurate analysis of the
sample gas and will also indicate the need for maintenance. A regular
calibration schedule should include recording of the zero and span pot values
for performance trends. Clogging of the sample system and other system
problems will usually show early symptoms during online analysis or during
calibration.
Problems with the system not due to the normal processing of the
sample are sometimes failures which must be corrected.
5.2 Filter
The system filter element (if included) should also be periodically
inspected. Replacement is recommended when the element begins to restrict
sample flow or upon visual inspection looks clogged and dirty.
NOTE: Although not normally included on basic Model 7320
analyzers, input protection filtering is always recom-
mended. Refer to the system piping schematic for recom-
mended hook-up.
5.3 NDIR Analyzer Measurement Cell
The Infrared Analyzer contains an auto zero circuit which
automatically zeroes the analyzer. This zeroing compensates for dirt in the
sample cell and, under normal circumstances, will compensate for very large
amounts of contamination in the cell. If there is a need for removing the cell
and cleaning it, follow this procedure:
A) Turn off power to the analyzer and open the optical bench
housing. Disconnect the cell heater wires (if present).
B) Remove the cell assembly from the optical bench. Non-sealed