Tankerman · Safety — Oxygen Analyzer
Before using a combustible-gas (explosimeter) reading to declare a tank's hydrocarbon level, the instrument requires that the atmosphere have:
- ASufficient oxygen, since a catalytic explosimeter needs oxygen to read correctly✓ Correct
- BLess than 5% oxygen
- CNo oxygen at all
- DOnly inert gas
Explanation
A catalytic-filament combustible-gas indicator needs oxygen to burn the sample and read accurately; it is unreliable in an inerted (oxygen-deficient) atmosphere. Tankscopes/measuring %LFL in inert conditions use a different instrument.
Authority: ISGOTT (gas measuring instruments)
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