SECTION V
4.3
FLUID LEVEL (ULLAGE) OF TANK OR OTHER VESSEL WHICH IS TO BE
GAUGED FOR OXYGEN PERCENT LEVEL:
4.3.1 Before entering the free space above a liquid level, the level of the fluid contained within
the tank or vessel should be known. If the location of fluid level is not known, it should
be determined by suitable and reliable means.
4.3.2 With the fluid level known, the oxygen sensor can be entered into the tank and unreeled
to the mid-point position of free space above and between the liquid level and tank top
CAUTION!
Under no circumstances should the oxygen sensor be immersed into fluid.
Immersion into fluid will disable use of the sensor unity until a thorough cleaning
and drying of the sensor cell is performed. However, this procedure may not always
return the sensor to an undamaged state, and sensor replacement should be
performed.
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