Teledyne T201 manual Maintenance Schedule, M501 NH3 Maintenance

4.0 MAINTENANCE SCHEDULE

The maintenance requirements of the T201 are the same as a standard T200 NOx analyzer but with additional maintenance items (Table 4-1). Please refer to Section 13 in the T200 Operator Manual for the T200 maintenance schedule and for maintenance and repair procedures.

The T201 requires the following additional maintenance items.

Table 4-1. Preventative Maintenance Schedule

Item	Maintenance Interval	Reference Section
NO2 molybdenum converter	Test every three months	Section 8.2.3 T200 Manual
M501 NH3 Converter	Test every three months	Section 4.1 of this manual
	Replace annually or as necessary
Reaction Cell	Clean annually or as necessary	Section 9.3.9 T200 Manual
AutoZero flow check	Quarterly as needed	Section 4.4 of this manual.

4.1M501 NH3 MAINTENANCE

The M501 NH3 external converter is operated at 825 ºCelsius. Because of this the stainless steel ¼” tube internal to the converter slowly oxidizes and may require replacement. Over time the converter’s efficiency will degrade, due to aging of the internal catalyst. This is characterized by a CONV value on the TNx channel of < 0.8 or > 1.2, despite the converter being at temperature. The efficiency of the converter should be checked quarterly. The converter should be cleaned out on a yearly basis by removing the outer tube and shaking the fine dust particles from both the outer and inner tubes. This is also a good time to replace the catalyst screen, if necessary.

The following procedure describes how to disassemble and replace converter parts. The various parts in the converter become delicate and brittle after prolonged exposure to high temperatures. It is therefore a good idea to have a complete set of replacement parts on hand before starting, as listed in Table 4-2.

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