[Drmike]

Hi all,

Does anyone know what the thread size is for the threaded brass hose
connectors (Mouthpiece to Lung connector)
I was thinking of making up a 4th cell adaptor. Has anyone got any
experience good/bad doing this for a MK15 series?

If someone knows the size it will save me buying a thread gauge

Cheers
Mike

[Skipbreather]

Hi Mike-

Not a lot of my rig is “original” but the connections from the center section to the hoses are purported to be original MK16 connections. The threads measure a nominal 1 ½ inches by 18 threads per inch. As a low tech cross reference, the outside diameter of the coupling nut measures approx. 1.78 inches.

Several years ago, to feed my VR3, I built a T piece for my intake hose that housed an R22D. Primary design goal was to make cell replacement easy. It was ugly, but it did work very well. One thing I learned the hard way: If you do this, be certain to use a high quality R22D sensor that includes a decent hydrophobic membrane, like Teledyne. My first efforts had some other brand w/o membrane. Rinsing the hoses after diving eventually killed it by water intrusion in a relatively short time. At first it would work once it dried out. Then readings were all over the place- useless.

Hope this helps,
Ken

[Drmike]

Thanks Ken,

I was thinking of using the new tiny sports kiss sensors.

Good point about washing.

The concept design I have at the moment has the sensor housing attaching to the scrubber and the (slightly shorter) exhale hose will connect to this via the original coupling. This should mean I can just remove the hose and wash as before without wetting the sensor. The only time that the sensor could be flooded would be when washing out the lung - but Ill just have to remember to remove the housing for that (or not tip the unit unside down)

Thanks again for your input.

Cheers
Mike

[Crazyduck]

Ken,

Simple question sir-

Is the sensor then just slipped into the gray hose and the upper hose clamp holds the sensor? The lower section is a PVC tee with the gray hose over it connecting to the sensor?

Do you know if anyone has tried to use quick disconnects for sensors? That way you could pop them off before cleaning?


Andrew

[Skipbreather]

Quote: (Originally Posted by Crazyduck)

Ken,

Is the sensor then just slipped into the gray hose and the upper hose clamp holds the sensor? The lower section is a PVC tee with the gray hose over it connecting to the sensor?

Andrew

Hi Andrew-

No, the cell is safely sealed up. Picture shows all the parts. The epoxy isn’t entirely necessary, but I used it to back up the seal on both sides of the Lumberg connector- belt and suspenders school of design. The cell gets top & bottom protrusions sliced off w/ razor blade. The ‘trick’ bit is the 2 inch section of bicycle inner tube. It slips over the trimmed cell, then is folded back onto itself to make two layers of inner tube over the cell. That makes it juuust the right size to slip nicely into the T, but too big to slide thru it since the T has a small lip inside.

Side note: Picture shows 3 wires connected. I later saw a blue print of the R22D on Teledyne’s website that has a small note saying the center pin is “not for customer use”.

Best,
Ken

[Crazyduck]

Ken,

Thank you.