Question for Inspiration divers

[scubaturek]

Have any of you considered that the moisture in the breathing loop isn't depositing directly on the sensor interface, but, instead, is creating a "bubble" on the surface, trapping gas there? Theoretically, this would create a static condition, causing the sensors to read the same proper O2 level, while the O2 level in the loop was actually dropping.

I refer you to the following: http://www.nobubblediving.com/inspirationpuffer.htm

Please note, I am not a RB diver, but am researching them avidly. I do believe they are diving's future.

Joe

 

[madmole]

That whole mod is based on a misunderstanding of an old sensor.

All new Inspiration sensors have a Teflon Hydrophobic membrane over the face. They therefore will automatically shed moisture. The design of the cells was also changed to allow more gas flow over their face (the plastic deflector was removed).

The moisture condenses on the cold walls of the scrubber unit, not the O2 cell faces as these will be at the same temp as the gas in the loop. Also the buble would need to be about 2" big to fill the tube and cover the sensor, you ever seen a bubble that big on the surface of water that doesn't have detergent in it?

The cells have your lung tidal volume going past them once every breath, thats a fair bit of a draft to move any moisture around

In fact the only way I know of introducing more tnhan usual moisture in the lid is to do a lot of large diluent flushes when running drills, thats exactly what this mod would do so I can see it making the condesation problem worse.

Note that none of the real Inspiration users have carried out this mod

 

[scubaturek]

However, could this have been a factor on older rigs, contributing to earlier casualties?

Joe

 

[madmole]

I seriously doubt it.

The bubble would have had to cover all 3 sensors to an equal amount (they are 2" apart). If any one was more of less effected (to within 10%) the alarm would have sounded.

Its easy to use the diluent to verify your sensor readings at any time or depth

 

[Tigerscuba]

I saw that article some time ago. I believe in theory it may be sound but not in reality. As posted earlier the O2 sens. are teflon coated and have a larger face than older versions. Also directing a shot of dilutent directly at the sensors may not be such a great idea. It is kind of a double edged sword. Any fod on the sensor may be imbeded into the face of the sensor. Also adding dilutent at depth will result in O2 addition so you are essentialy using gas from both bottles. I am confident that with proper training, predive inspections and regular maintenence this should not be a factor.