Disposable CO2 and O2 sensors

Nad

Interesting like also the Sentinel has some of the above features:

Temperature, respiratory monitor and photosensor...
We're little by little following the same and correct way?!

Nad

__________________
The Impossible is often the Untried

Ilikerisk

Did you find anything out?

robertkarlsson

Hello Alex, was just wondering about if you had the time to try the smsi oxygen
sensors yet:

Oxygen Sensor


Cheers

deepwrecksc

It will be interesting to see if optical sensors become viable for O2 measurement in life-support systems like CCRs. Fluorescence-quenching based oxygen measurement has been around for quite some time in the analytical chemistry and oceanography communities. We use these coupled with fiber-optic spectrometers often for microscale measurements of oxygen in biological and environmental samples. The problem is that often the fluorophores tend to photobleach, leading to calibration and linearity problems. In addition, like all chemical reactions there is a temperature effect and therefore for maximum accuracy the sensors must be calibrated under the same conditions in which they are going to be applied. My experience has also been that with existing oxygen optodes the linear dynamic range is limited to < 1 ATA O2. There is a saturation problem beyond this level (essentially the fluorescence is entirely "quenched" at this point).

I am not saying it isn't possible (maybe someone's even diving a system based on this technology), but take this for what it is worth: when I am doing experiments that are "off the cuff" or non-critical, I have no trouble using a fluorescence-based optode. However, if I'm going to publish the data or if I absolutely NEED to be confident of my 02 values, I'm still going to use a galvanic cell. With the current technology that I'm aware of, I would not trust my life to fluorescence-quenching based oxygen sensors.

AD_ward9

I am glad that some of the things we have been pioneering are finding their way into sports products. We compete commercially, not by hiding bits of safety information, and therefore welcome these moves. We have provided the details of some of the algorithms to companies that have asked, as well as the material on our web site. Auto-turn on with falling PPO2 is something no-one has any excuse not to use, and it will save lives. Use of auto-loop shut off valves (for a tiny licence fee), would save even more.

The O.R. eCCR has been released by us in a small batch for saturation divers. We are busy doing some operational upgrades to it just now, mostly relating to upgrading to true wet mateable connectors instead of a Fischer type. A bigger upgrade than it sounds.

On the O.R. sports rebreather, the safety work looking at accident figures led us to change track a bit, concluding that the best configuration for sports divers is a mCCR but with excellent monitoring (including CO2 sensor, PPO2 hazard alarm that does not use O2 sensors, the same O2 sensor fusion technology we have in the commercial rebreather etc). The market for sports units is tiny, and demands a lot of support, so we were not rushing to release this, but an event a month or so ago where someone tried (and failed) to block publication of our safety data pissed me off so we will release it as fast as we can get manuals written. We have all mouldings for the rebreather now. Plan is sale at US $995, and monitoring costing about the same. It will be possible to buy it separately from the monitors, with a CE approval. I will post pictures in a month or so: I am going diving with it and a twin unit for a few weeks later this month. On the eCCR for sports use, it requires a lot more work still: this is something we are doing, to hit SIL 4 safety levels in that application involves dealing with more things than you might imagine.

As well as the commercial and professional eCCRs we had at DEMA last year, we plan to have the mCCR sports unit at DEMA this year. They will probably be ready for shipment to customers by end of the year.

On the sol-gel sensor, the company that makes it is very small and academic: it required an NDA before it supplies samples (at $500), which prohibits publication of results to third parties, and at their request one has to destroy all data obtained from testing the samples. I have not seen an NDA of that form for a sample of a production product in the 33 or 34 years that I have been employed in design work. I don't like working with academic companies: the unrealistic expectations cause too much pain - I prefer to wait until they grow up. Their MOQ is 500 units. The restriction on issuing test results means a device incorporating it could not get CE approval under PPE - who would audit it? In speaking to the company I am quite certain they have never done any proper testing for suitability for use in rebreathers, so their claims for this application are somewhat hazardous. We would be prepared to do testing of this sensor if the supply did not have these distracting NDA elements. I think most mature companies would have the same sort of problems with their terms, so we are just watching it for now. There are lots of other companies working with sol-gels and who have O2 sensors as prototypes, and from those we are aware of problems with sol-gels in helium, premature failure, contamination and also problems under pressure, so this is not a walk in the park.

Alex

Hanssing

Cough cough....

If it makes it target-price , I'll do something I never thought - own two units

Date is now 11/-06-2008, I'll be looking for pictures ultimo July

Assuming the prices are your estimates I'm thinking who ever chooses to buy the license and produce it, can do so at their own price, so the target-price is just a guess right?

Or are Deeplife going to compete against its own customers?

Best
Nicolai

__________________
Woohooo - I can change my rEvo!
Its going to be bitchin' tricked out piece of gear

AD_ward9

We have a deal with a pseudo-client to sell at this price, based on the sports mCCR we have now. All tooling is done, and has been for a while. This means the price is pretty firm.

Our existing clients are focused on professional diving, using the eCCR products, so this does not cut across things. Training arrangements agreed in principle and are now being fleshed out.

Pictures will be posted by 15th July (I get back from ocean trials with it on 10th July, all going well). mCCR has had all the machine testing one can imagine already, including EN14143.

Alex

David Pye

I want to start picking at details but suspect that isnt what you want :-)

I do like the price idea though!

Quick Q tho: Front or back mounted counterlungs? :-)

AD_ward9

Back.
Alex

Hanssing

Well if thats directed at me, then all I can say is that I was originally waiting for the OR - then thought that it would never come, be too exspensive, and I wanted a "safe" CCR now - so I went with the rEvo.....

But I still like the OR, and for some reason, I allway swant to be one of the first lemmings going over the cliffs when its a toy I like :-)

We'll see. I'll certainly look forward to it!

Nicolai

__________________
Woohooo - I can change my rEvo!
Its going to be bitchin' tricked out piece of gear