Cosmos XP-3180, Инструкция по эксплуатации

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Detection Principle
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Galvanic Cell Type (Oxygen)
It consists of a noble metal electrode, a base metal electrode, and an electrolytic solution.
A noble metal electrode has contact with the air through the Teflon membrane.
Due to the electrical potential difference from the load resistance caused by connecting to both
terminals, the following reaction takes place:
Noble metal electrode O
2
+ 2H
2
O + 4e
- →
4OH
-
Base metal electrode 2Pb
→
2Pb2
+
+ 4e
-
As a result, the electrical current commensurate with the oxygen concentration level in the air flows
from the noble metal electrode to the base metal electrode through an external circuit. Because the
electromotive force is temperature-dependent, a thermistor is used to compensate for the variation
in ambient temperature.
21 vol% adjustment: To adjust meter in fresh air to 21 vol% indication.
Explosion-proof: A structure applied to electrical equipment to prevent the equipment from igniting the
surrounding explosive atmosphere as the source of ignition.
Intrinsically safe design: A structure whose inability to ignite explosive gases with a spark of electricity or
a hot section generated in normal time or an accident has been confirmed in fire
and other tests.
Non-hazardous area: A place where there is no possibility that an explosive gas will mix with the air under
ordinary or abnormal circumstances and reach the explosion limit.
vol %: Gas concentrations given in terms of percent of cubic volume
(Partly cited from the Industrial Gas Detectors Monitor Association, Glossary of Gas
Detector Alarms, and Glossary of Detection Tube Type Gas Measuring Instrument)
11. Detection Principle
12. Glossary