Quote: (Originally Posted by
heyydude)
Here's the thing: The system we have now, with the Sensors across the inhale/exhale side of the loop works very well. It's worked on the Meg and the Cis, as Joe pointed out.
Anyway, the purpose of this post was to say that we have taken into account the debate over the sensor placement, and are looking into alternatives (which themselves, have negatives)
Kevin, ever since sensor have come apart (no matter how rarely it happens) many of us have been vary of such a design, to say the least.
What are the advantages, the arguments
for this design?
Or at least against the more common design of having the entire cell on the inhalation side?
MK series, AP CCRs, your own Hammerhead replacement lid for them, PRISMs, etc all have the sensors on the inhalation side only, and they all seem to work just as well.
Quote: (Originally Posted by
silent running)
I remember now that the flood tolerance/flow direction has been debated before. But I'm not sure that's accurate, as I don't know of any Prism or other in-out radials that have ever flooded or been tested with 1 ltr of water.
Andy, I'm with Joe on that one, the PRISM scrubber isn't very flood tolerant. It's a simple matter of math, the center tube doesn't have much volume, certainly less than spacers used on the bottom of many scrubber generate. In the PRISM's bucket that space is used to accumulate condensation, not act as a water trap. Nor does the PRISM's design allow for a drain valve just before the scrubber, as the Sentinel has and many units could have.
The PRISM's counterlungs work very well as water traps and allow water to be purged. That may make up for the most common reason for water in the bag, bad mouthpiece protocol, but it doesn't help much if water gets into the loop past it (most likely at the exhalation hose to head connector, or the hose itself).
SMI had different priorites as they pursued a naval contract. 300 mins scrubber duration, max weight ready to dive 50 lbs, etc ... I remember an ad being run giving a couple of those specs in a commercial diving magazine. So SMI went for the needed duration.