Mk 15 Upgrades

doug anderson

Hi,

You are bang on hoppy. The big display is the secondary. It will display voltage or PPo2, individual readings or mean, direct from the sensors and will also display what the primary side is "seeing" too just in case you want to check. The primary is very much in the old style. Row of LED's for status in relation to setpoint. Two switches on the back. One for changing setpoint and one for manual addition (fires solonoid) of Dil or O2. There are a bunch of other features and set up's but that is basically it.

Doug

doug anderson

Hi Dave,

I just reread you post and you are right of course. There is no analogue display from the cells. The voltage is split and processed by an A/D converter I think in a small module just below the tree.

Doug

caveseeker7

Thanks for the pictures and explanation, much appreciated.

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Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

LagunaResearch

Hello all,
Thanks Doug for doing the ground work. First, we've been very busy getting everything just right. Life support systems are not something that we wanted to bust put out there - as it is it's been about 7 years in the making. So, I have to apologize for not posting stuff along the way. If there have been concerns, I'd just wish that people would call. It's a lot easier to talk on the phone (while doing other things) than reading and posting. I suspect I'll have to hire someone just for this task!!

We've been developing and continuously using our systems in our guinea fish testers... and we appreciate them all.

Anyway - here's the details on the sensors and secondaries. The O2 sensors are individually double buffered on the sensor array. Both data paths (primary x 3 and secondary x 3). Power for the buffers are sourced from both the primary and/or secondary devices. So, the net effect is that yes you can have our system and you favorite other secondary - but I'd have to ask why? When our UDC is excellent!!!

The sensor voltages are processed thru an ADC, but at the device level (UDC, CCM). The UDC and CCM provide individual Sensor mV, PPO2 or an aggregated output. The UDC can be used to display what the CCM sees or what the UDC sees, either way. The ILD is an LED visual device whereas the UDC has both the LEDs and a large LCD.

No we do not have a device that is akin to an analog meter directly measuring the analog output of the sensors where the meter face is calibrated in PO2... But we do have a secondary device - independent in all respects and that's the UDC.

The MK15 Kit has changed as Doug has mentioned, in that the gas piping was originally SS. That posed to much of a problem with respect to electrolysis - we did an intermediate solution (that I liked) with PFA tubing and have now finished making swaged hoses from the CCM to the MK15 piping for a more robust connection - I can't think anyone will complain now. I'll have to update the conversion manual and then will post it.

More later.

__________________
Wayne Miller
Laguna Research, Inc
www.lagunaresearch.com
949-484-4515v
530-468-2257f

caveseeker7

Doug or Wayne, would either one of you post a picture of the HUD, please.

Oh no you don't. You'll have to make time for us!

Thanks for the post.

__________________
Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

Dave Sutton

Nice to see you here, and thanks for taking the time to reply.

Is the substitute tubing able to withstand 3000 PSI in case of a first stage HP seat failure? That is one of the primary design benefits of the SS tubing, and in fact a Mark-15 can tolerate a full HP seat failure and the only real difference is that the ADV Schraeder locks and no longer acts as an ADV. This is why we looked askance at the SM-1600 version, which used plastic tube to replace the SS lines originally used. The Mark-15 ADV is an upstream design, so it does not act as a pressure relief valve, and there is no relief valve anywhere in the 02 system either. The original architecture did not require relief in case of a HP seat failure. Removal of that capability might not be troublesome to a user from a "will work after HP seat failure" viewpoint, but if no relief valves are added to compensate, you will have a blown hose immediately after any HP seat failure, causing catastrophic loss of the affected pneumatic system. That then requires either a change of the first stage, or an extra port added in each pneumatic system and an OPV added at that point.


Dave

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Drmike

very interesting....can you tell me why you favour the cell type change?


personally I wouldnt want Molex connectors on my MK15.5

I strongly favour SS piping (having had a SM1600 and converted it back)

I strongly hate plastic cable glands!

I pressume your developed this to tender for the USN MK16 upgrade contract?

I need to upgrade my MK15.5 and have a new horseshoe board to go in but guess your system doesnt need that.

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Wreck diving is a sport
Diving in general is a sport

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LagunaResearch

With regard to the tubing change... SS is definitely much more durable than anything else - just a pain to fabricate. The only problem that we have found (and solved) was the electrolysis issue with the anodized cases. So to fix that we just attached a sacrificial anode to the tubing and all was well. So we still have the SS tubing kits as well.

However, we liked the flex of the PFA tubing. We eventually ended up with the standard swaged rubber hose - for better wear issues and easier fabrication/installation.

The overpressure issue can be solved be installing a overpressure valve on the CCM on either (or both) the O2 and Diluent lines. We have an extra port on the CCM, on both sides - pre-solenoid, for such a reason.

__________________
Wayne Miller
Laguna Research, Inc
www.lagunaresearch.com
949-484-4515v
530-468-2257f

deepwrecksc

How about using thick-wall PEEK tubing instead of SS or PFA? We use it often in high performance liquid chromatography (HPLC) applications for chemical research up to >3000 psi (rated to this pressure with a 2 mm bore). It is available in 1/8" and is much easier to cut and form than SS. It also works very well in SS Swagelok fittings. No electrolytic corrosion worries and this stuff is a highly inert technopolymer suitable for use with O2.

Check out Upchurch Scientific HPLC and Fluid Transfer Components (Upchurch Scientific).