O2 cells falling apart - bad batch?

divetheworld · 1st April 2007, 10:28

Quote: (Originally Posted by teksimple)

Good question. My web site opening was delayed because the newly re-worked PSR-11-39MD sensors were not out of the factory yet. I do not know the specific changes, but I assume they had to do with impact resistance?

An honest answer, cant be fairer than that.
If you can find out and let us know?

Thanks mate.

Brent

teksimple · 1st April 2007, 10:34

Quote: (Originally Posted by Drmike)

Happened to me and a buddy a while ago with 2 new inspirations- Posted here somewhere (or on YBOD list) might need to do some searching, Resulted in buddy toxing

No, I do remember a while ago Mike that you warned about doing a sanity flush. I did not remember linking that incident with a certain thread. Since then I have (almost) always done sanity flushes and have my girlfriend doing them to. (By the way, she was impressed that the box of sensors I was packing on Thursday for Singapore was yours).

I would hate to say that my success with AII sensors is as much luck as anything, but I will bite some humble sandwich here and say no more.

silent running · 1st April 2007, 14:54

Quote: (Originally Posted by n2diving)

I'm going to have to go strongly on the side of not replacing all of them at once either. The 'bad batch' problem occurs much too frequently, and it was a regular occurance with the Teledynes... and I've had one such occurance with the AI's.

Hello n2diving, it's my understanding that the Prism O2 sensors, which are made by AI, are shipped from the manufacturer as a mixed batch, meaning the orders are made up of sensors from different manufacture dates. Maybe this was only done at the request of SMI, but it seems like a sensible proceedure and maybe other wholesalers of AI sensors should ask them to do the same... -Andy

AD_ward9 · 2nd April 2007, 06:38

Quote: (Originally Posted by divetheworld)

An honest answer, cant be fairer than that.
If you can find out and let us know?

Changes on the -MD relate to:
1. Clearer date marking (new labels, no date code). So SEPT O7 says just that.
2. Colour coded for the year.
3. Four different changes to improve the mechanical robustness. For dive applications, these improvements are essential.

I understand all these have been done (we have tested 12 units with the mechanical improvements and the factory confirmed the date/colour issue) and you should be able to order them now. I am told they are on a 12 day lead time.

For the -DC it uses a different pcb, with the SMB connector. This is just getting the production going, but we were quoted 12 day lead times on those also.

Alex

AD_ward9 · 2nd April 2007, 06:44

Quote: (Originally Posted by divetheworld)

Its a shame the data backing up the claim that the Teledynes were "found to be unsuitable for diving applications." is not present.
I'm none the wiser either way as a result of this at present.

If you are using the sensors on a large scale for diving, we can release the Teledyne data to you subject to us closing an NDA. PM me for it.

I have indicated the range of problems we identified with the Teledyne sensors and wish to leave it there publically. This is so Teledyne can work discretely to address the issues and bring a suitable quality product to market in the not to distant future. We should all give them grace to do that, as it is not good for any here to be in a single supplier situation.

Quote: (Originally Posted by schford)

Unfortunately I know of one fatality where it is likely that is what happened.

But nothing stops you buying a batch of cells at a time (I do) - just change them one at a time to check all is ok and check they are not current limited at 6m at the start of your dive.

It might mean it is a 3 by 5 min job rather than 1 by 5min job but ......

I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness.

The 6m check should be carried out always, (I believe above 6m, the Rebreather should be used a pure O2 system, so the check for a ceiling fault would be automatic), but not using all sensors from one batch is a further necessary precaution.

Alex

divetheworld · 2nd April 2007, 12:13

Quote: (Originally Posted by AD_ward9)

If you are using the sensors on a large scale for diving, we can release the Teledyne data to you subject to us closing an NDA. PM me for it.

Thanks.

How long will you give the manufacturers to respond before you release the information to the general public?

AD_ward9 · 3rd April 2007, 03:12

Quote: (Originally Posted by divetheworld)

Thanks.

How long will you give the manufacturers to respond before you release the information to the general public?

It will be released as soon as the manufacturer's work to address the issues is completed, with a year as an end-stop.

Alex

**UWSojourner** · 3rd April 2007, 04:38

Quote: (Originally Posted by AD_ward9)

I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness.

Is the slow response time something that can be seen in calibration at 100% O2? Or is the response time at higher PO2s slower than the response at lower PO2s?

what2be · 3rd April 2007, 04:58

Quote: (Originally Posted by AD_ward9)

I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness.

The 6m check should be carried out always, (I believe above 6m, the Rebreather should be used a pure O2 system, so the check for a ceiling fault would be automatic), but not using all sensors from one batch is a further necessary precaution.

Alex

Can you provide the names of any rebreather mfg (not a diy) that provides new units with new and used cells? If this is such a issue I would think the mfg's would back your data up and do this. After reading how dangerous it is to use all new cells, im assuming they wouldnt want to go kill people and get themselves sued unneccesarily. Also, what brand were the batch of sensors that had a slow response time?

divetheworld · 3rd April 2007, 06:46

Quote: (Originally Posted by UWSojourner)

Is the slow response time something that can be seen in calibration at 100% O2? Or is the response time at higher PO2s slower than the response at lower PO2s?

slow response can be seen throughout the voltage range. Its what causes a cell error on your descent but reaches a common output after a short time. Slow response does not mean current limited, you can still burn a 1.6 with a slow cell.
In constant depth range, the typical ECCR controller will function normally with a slow cell.

Quote: (Originally Posted by AD_ward9)

It will be released as soon as the manufacturer's work to address the issues is completed, with a year as an end-stop.

Alex

Thanks Alex, more than reasonable.

1st April 2007, 10:28	#41 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,586	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by teksimple) Good question. My web site opening was delayed because the newly re-worked PSR-11-39MD sensors were not out of the factory yet. I do not know the specific changes, but I assume they had to do with impact resistance? An honest answer, cant be fairer than that. If you can find out and let us know? Thanks mate. Brent __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe
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1st April 2007, 10:34	#42 (permalink)
teksimple Enlightened Alpinist Current Rebreather/s: MK 15.X Other Rebreather/s: Sport Kiss Classic Kiss Join Date: Apr 2005 Location: Back in Hawaii Posts: 503	Re: O2 cells falling apart - bad batch? Quote: (Originally Posted by Drmike) Happened to me and a buddy a while ago with 2 new inspirations- Posted here somewhere (or on YBOD list) might need to do some searching, Resulted in buddy toxing No, I do remember a while ago Mike that you warned about doing a sanity flush. I did not remember linking that incident with a certain thread. Since then I have (almost) always done sanity flushes and have my girlfriend doing them to. (By the way, she was impressed that the box of sensors I was packing on Thursday for Singapore was yours). I would hate to say that my success with AII sensors is as much luck as anything, but I will bite some humble sandwich here and say no more. __________________ ---- _____________ "I don't know the percentage of the Internet that's valid, do you? Jesus, it's scary." - Hunter S. Thompson Last edited by teksimple : 1st April 2007 at 11:13. Reason: The person of whom I was thinking was diving a Meg
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1st April 2007, 14:54	#43 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,832	Re: O2 cells falling apart - bad batch? Quote: (Originally Posted by n2diving) I'm going to have to go strongly on the side of not replacing all of them at once either. The 'bad batch' problem occurs much too frequently, and it was a regular occurance with the Teledynes... and I've had one such occurance with the AI's. Hello n2diving, it's my understanding that the Prism O2 sensors, which are made by AI, are shipped from the manufacturer as a mixed batch, meaning the orders are made up of sensors from different manufacture dates. Maybe this was only done at the request of SMI, but it seems like a sensible proceedure and maybe other wholesalers of AI sensors should ask them to do the same... -Andy
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2nd April 2007, 06:38	#44 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,862	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by divetheworld) An honest answer, cant be fairer than that. If you can find out and let us know? Changes on the -MD relate to: 1. Clearer date marking (new labels, no date code). So SEPT O7 says just that. 2. Colour coded for the year. 3. Four different changes to improve the mechanical robustness. For dive applications, these improvements are essential. I understand all these have been done (we have tested 12 units with the mechanical improvements and the factory confirmed the date/colour issue) and you should be able to order them now. I am told they are on a 12 day lead time. For the -DC it uses a different pcb, with the SMB connector. This is just getting the production going, but we were quoted 12 day lead times on those also. Alex
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2nd April 2007, 06:44	#45 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,862	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by divetheworld) Its a shame the data backing up the claim that the Teledynes were "found to be unsuitable for diving applications." is not present. I'm none the wiser either way as a result of this at present. If you are using the sensors on a large scale for diving, we can release the Teledyne data to you subject to us closing an NDA. PM me for it. I have indicated the range of problems we identified with the Teledyne sensors and wish to leave it there publically. This is so Teledyne can work discretely to address the issues and bring a suitable quality product to market in the not to distant future. We should all give them grace to do that, as it is not good for any here to be in a single supplier situation. Quote: (Originally Posted by schford) Unfortunately I know of one fatality where it is likely that is what happened. But nothing stops you buying a batch of cells at a time (I do) - just change them one at a time to check all is ok and check they are not current limited at 6m at the start of your dive. It might mean it is a 3 by 5 min job rather than 1 by 5min job but ...... I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness. The 6m check should be carried out always, (I believe above 6m, the Rebreather should be used a pure O2 system, so the check for a ceiling fault would be automatic), but not using all sensors from one batch is a further necessary precaution. Alex Last edited by AD_ward9 : 2nd April 2007 at 07:03.
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2nd April 2007, 12:13	#46 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,586	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by AD_ward9) If you are using the sensors on a large scale for diving, we can release the Teledyne data to you subject to us closing an NDA. PM me for it. Thanks. How long will you give the manufacturers to respond before you release the information to the general public? __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Last edited by divetheworld : 2nd April 2007 at 12:35.
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3rd April 2007, 03:12	#47 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,862	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by divetheworld) Thanks. How long will you give the manufacturers to respond before you release the information to the general public? It will be released as soon as the manufacturer's work to address the issues is completed, with a year as an end-stop. Alex
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3rd April 2007, 04:38	#48 (permalink)
UWSojourner Pacific Northwest Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Location: Portland Oregon Posts: 556	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by AD_ward9) I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness. Is the slow response time something that can be seen in calibration at 100% O2? Or is the response time at higher PO2s slower than the response at lower PO2s?
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3rd April 2007, 04:58	#49 (permalink)
what2be New Member Current Rebreather/s: Evolution Other Rebreather/s: Join Date: Apr 2006 Location: Eureka, Ca Posts: 94	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by AD_ward9) I agree, there has been at least one fatal accident where simultaneous cell failure is implicated, but warn that the 6m check is not enough if someone changes all the sensors at the same time. One of the failure modes we found was batches of sensors (not AI) with very slow response time. This means it appears that the flush simply takes longer to work but you eventually get to the right number. For the rebreather controller, it operates with the wrong number on a fast ascent: wrong enough for the diver to lose consciousness. The 6m check should be carried out always, (I believe above 6m, the Rebreather should be used a pure O2 system, so the check for a ceiling fault would be automatic), but not using all sensors from one batch is a further necessary precaution. Alex Can you provide the names of any rebreather mfg (not a diy) that provides new units with new and used cells? If this is such a issue I would think the mfg's would back your data up and do this. After reading how dangerous it is to use all new cells, im assuming they wouldnt want to go kill people and get themselves sued unneccesarily. Also, what brand were the batch of sensors that had a slow response time? __________________ "If I die with any money at all in my bank account I know I miscalculated"
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3rd April 2007, 06:46	#50 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,586	Re: O2 cells falling appart - bad batch? Quote: (Originally Posted by UWSojourner) Is the slow response time something that can be seen in calibration at 100% O2? Or is the response time at higher PO2s slower than the response at lower PO2s? slow response can be seen throughout the voltage range. Its what causes a cell error on your descent but reaches a common output after a short time. Slow response does not mean current limited, you can still burn a 1.6 with a slow cell. In constant depth range, the typical ECCR controller will function normally with a slow cell. Quote: (Originally Posted by AD_ward9) It will be released as soon as the manufacturer's work to address the issues is completed, with a year as an end-stop. Alex Thanks Alex, more than reasonable. __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Last edited by divetheworld : 4th April 2007 at 08:47.
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