Hollis Explorer User Manual - page 55
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If there is no peak, then there is a problem with the scrubber. This could be
caused by:
1. Flooded scrubber
2. Scrubber pack not installed
3. Scrubber pack empty
4. Scrubber material exhausted or gone bad
During pre-breathe, the unit needs to be breathed on to see a change in
the thermal profile. This does not guarantee correct operation, but has a
high likelihood of correct operation. Any sense of dizziness, nausea or oth-
er CO
2
symptoms should also be used to alert the diver that the scrubber
is not operating correctly. A small bypass due to a badly fitted scrubber or
CO
2
seals could give a scenario of a good peak, but an excessive amount
of CO
2
could still bypass the scrubber. If this occurs, stop breathing on the
EXPLORER. This will be indicated (and alarmed for) by the optional Gas-
eous CO
2
sensor accessory. Replace the absorbent and/or check scrubber
packing and seating.
! CAUTION: Pre-breathing any rebreather should be done in a safe
seated position, with their nose plugged, where the diver can
monitor displays and any potential symptoms of CO
2
poisoning.
Pre-breathing should never be conducted while walking or stand-
ing in a place where the diver could fall into the water or injure him
or herself.
The actual minutes remaining number displayed to the diver comes from
the Nitox Injection Monitor. This gives a consistent and reliable reading of
current absorbent duration based on nitrox injection.
Always remember to reset the absorbent duration when a new scrubber is
fitted. You will be prompted to do this during the Pre-dive sequence (Fig
3.21).
!
DANGER: DO NOT reset the absorbent duration unless a new
scrubber with fresh absorbent has been fitted.
Always change the absorbent when the low filter (scrubber) alarm appears,
or before if you suspect the absorbent is not operating correctly or close to
the end of its life - be conservative - be safe.
!
DANGER: If you do not insert an absorbent scrubber pack, the de-
vice greatly restricts breathing on the loop. This is to force you off
the breathing loop until the issue is remedied. You must not dive
without a CO
2
scrubber pack fitted.
Fig. 3.21
3
.1
4