Emerson Rosemount X-STREAM O2 Transmitter, Инструкция по эксплуатации

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Instruction Manual
IM-106-910C, Rev. 1.0
November 2009
3-7
Hazardous Area
X-STREAM O
2
Transmitter
NOTE
Make sure the DCS is configured for the same range as the Xi. For instance:
-1% O
2
to 10% O
2
.
Programmable
Reference
The zirconium oxide sensing technology has historically measured process
oxygen by using ambient or instrument air as a reference (20.95% oxygen).
The sensor develops most of its signal at the low oxygen levels typically found
in combustion flue gasses (2-4% oxygen), and is most accurate at these
levels. When measuring near 20.95% O
2
, the sensor develops only a few
millivolts of signal, and accuracy degrades.
The programmable reference feature permits the user to use a bottled
reference gas of low oxygen value (0.4% oxygen recommended). When
measuring at or near 21% oxygen, a strong negative oxygen signal results,
with much improved accuracy. A bottle of reference gas typically lasts about a
month at the low flows required. Typical applications would be:
Flue gas recirculation -
controlling the mixing of flue gasses into the burner
windbox prior ahead of the burner to reduce NOx emissions.
Moisture monitoring -
measuring the amount of moisture coming off of
industrial dryers by noting the dilution effect water vapor has on the normal
20.95% ambient drying air. (Non-combustion drying processes only.)
Enriched oxygen concentration -
pure oxygen is sometimes mixed in with
the combustion air to increase heat at the flame. This is used in steel and
other metals reduction processes and in some catalyst regenerators.