270NH3.MAN.REVD.062019
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Shutdown
1. It is recommended to introduce inert gas or instrument air through the cal gas port for 15 to 30
minutes to purge the filter chamber, NH
3
converter, and sample lines of potentially hazardous
substances.
2. Shut down the sample pump before the end of the purge cycle to avoid drawing in new gasses.
3. Filter replacement may now be safely performed. Caution: The filter chamber is typically controlled to
temperatures above 300°F and can cause serious burns.
4. For further disassembly, shut down all heaters in the probe and converter.
5. It is recommended to flow instrument air through the converter for several hours to cool down to
acceptable temperatures. Caution: The NH3 canister operates at temperatures above 1250°F and
can cause serious burns. Depending on the installation and application parameters, the well-
insulated chamber may take up to 24 hours for a sufficient cool down period.
6. Turn off instrument air for blowback and manually perform a blowback cycle to empty the accumulator
chamber and reduce any stored energy in the system.
