O2 sensors - What you DON'T KNOW - FAILURE!

SteveL · 7th November 2006, 11:24

Quote: (Originally Posted by Gene_Hobbs)

Thank you for the post!

Rubicon Research Repository
Evaluation of Analytical Industries Inc. Model Number PSR-11-33-NM Oxygen Sensors for Use With the MK 16 MOD 1 Underwater Breathing Apparatus
Rubicon Repository ID#: 123456789/3536

Unmanned Test and Evaluation of the Teledyne Analytical Instruments R-10DN Oxygen Sensor for Use in the MK 16 Mod 1 Underwater Breathing Apparatus
Rubicon Repository ID#: 123456789/3466

We have more like these on hand but lack of funds and time will be a limiting fcactor on when we can get to them. There are also reviews of failures in most evaluations done on different systems (Several in the Repository already).

Slightly off topic but interesting on recording of O2 sensor data.
DESIGN OF AN UNDERWATER TELEMETRIC SYSTEM FOR REBREATHERS
Rubicon Repository ID#: 123456789/3715
abstract

Interesting - I am using the R10 DS cells which have a faster response time but ar magnetic (i assume)

I went for a dip on the w/e and all the cells were working fine and calibrated perfectly - then suddenly without any warning one of the cells just went tits up and died - measured it on the surface and it is at 3mV instead of the usual 21- 24mv like the others.

Any ideas??

They are less that one year old.

Steve

Scubascooby · 7th November 2006, 12:11

Quote: (Originally Posted by sabgia)

One CL is below upstream of sensors, the other is below but downstream thus balancing the pressure. The cells don't carry any pressure on the Meg

!

I have experience with 6 Teledyne R22's. 1 lasted 1 week

, 2 about 6 months

, 1 operates still after more than a year

. The other two are about 4 months old and going good.

I don't know the internal of the Meg but does the o-ring of the cell prevent gas passing to the rear of the cell ? Put another way, how is pressure equalised across the cell ?

Peter

decoweenie · 7th November 2006, 12:27

Quote: (Originally Posted by Scubascooby)

...Put another way, how is pressure equalised across the cell ?

Thru the sorb.

The sensor body is on the exhalation side, the sensor face is on the inhalation side (from reading the ANDI Meg manual).

RonMicjan · 7th November 2006, 12:47

due to grammatical errors in the "report" it is difficult to determine if the failure report was directed to the diver or to the manufacturing process.

It seemed that the analyst was telling his boss in the report "I told you molding those cases was going to come back and bite you"

Does anyone know if there are multiple part numbers for this sensor, one being made with a molded cell housing and one with a machined version? I seem to recall seeing some black sensors that looked machined, I know my current cells are molded due to the seam on them.

RonMicjan · 7th November 2006, 13:04

How about completly off topic

Quote: (Originally Posted by Gene_Hobbs)

Thank you for the post!

Rubicon Research Repository
Evaluation of Analytical Industries Inc. Model Number PSR-11-33-NM Oxygen Sensors for Use With the MK 16 MOD 1 Underwater Breathing Apparatus
Rubicon Repository ID#: 123456789/3536

Unmanned Test and Evaluation of the Teledyne Analytical Instruments R-10DN Oxygen Sensor for Use in the MK 16 Mod 1 Underwater Breathing Apparatus
Rubicon Repository ID#: 123456789/3466

We have more like these on hand but lack of funds and time will be a limiting fcactor on when we can get to them. There are also reviews of failures in most evaluations done on different systems (Several in the Repository already).

Slightly off topic but interesting on recording of O2 sensor data.
DESIGN OF AN UNDERWATER TELEMETRIC SYSTEM FOR REBREATHERS
Rubicon Repository ID#: 123456789/3715
abstract

wow gene, thanks for the short game of pursuing the wild foul, how about posting something relevant next time.
For those of us who may not want to register with the "RUBICON Foundation", NEDU has this same report here, but I warn you, it has nothing to do with the current discussion.
http://stinet.dtic.mil/cgi-bin/GetTR...c=GetTRDoc.pdf

Crazyduck · 7th November 2006, 13:45

Ron,
Didn’t Alex have a thread were he talked about the problems with design, contamination of the electrolyte and quality control issues? He broke it down on a study they did to check the practical issues and problems with the sensor design.

The only black sensors I have seen were the Analytical Industries materials. Not sure how they were made. However, the fallout rate seems better by some people’s standards.

Then again there are medical grade sensors- but the high output range is beyond the relative output of the R22 range. However, that does not require amplification.

Please checkout this thread-
http://www.rebreatherworld.com/gener...+contamination

Nice posting on the hijack buddy- I hate having to register to see information that is in the public domain.

Later, Andrew

Scubascooby · 7th November 2006, 14:51

Quote: (Originally Posted by decoweenie)

Thru the sorb.

The sensor body is on the exhalation side, the sensor face is on the inhalation side (from reading the ANDI Meg manual).

That's interesting. So if the divers rolls from side to side there will be
small pressure differences across the cell for a short period of time.
Not enough to cause damage to the cell body I would imagine.

RonMicjan · 7th November 2006, 15:44

Quote: (Originally Posted by Scubascooby)

That's interesting. So if the divers rolls from side to side there will be
small pressure differences across the cell for a short period of time.
Not enough to cause damage to the cell body I would imagine.

Not likely, or likely not measurable, the points are at isobaric levels but the gas can easily equalize pressure through the scrubber stack. you are making an assumption based on an assumption, the first post on differential pressure was inaccurate also.

Good eye andrew, I remember that post, its a good read.

Danil · 7th November 2006, 18:01

OK, the ONLY time you have a mesurable pressure difference on the cells in the MEG is when you test the sensor carriage assembly for loop integrety in your predive checks.
But, it´s kind of fun reading other folks assumptions...

Gilles · 7th November 2006, 21:16

Quote: (Originally Posted by Scubascooby)

I don't know the internal of the Meg but does the o-ring of the cell prevent gas passing to the rear of the cell ? Put another way, how is pressure equalised across the cell ?

Peter

The front and back of the cells are connected throgh the sorb. Thus the only pressure the cells experience is the drop across the sorb.

As mentioned by Dan above, a pressure-drop exists only when its tested for loop integrity!

Earlier posts (that were incorrect) deleted.

7th November 2006, 11:24	#11 (permalink)
SteveL Custom Title Allowed! Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Join Date: Nov 2005 Location: Sydney Australia Posts: 222	Re: Rubicon Research Repository Quote: (Originally Posted by Gene_Hobbs) Thank you for the post! Rubicon Research Repository Evaluation of Analytical Industries Inc. Model Number PSR-11-33-NM Oxygen Sensors for Use With the MK 16 MOD 1 Underwater Breathing Apparatus Rubicon Repository ID#: 123456789/3536 Unmanned Test and Evaluation of the Teledyne Analytical Instruments R-10DN Oxygen Sensor for Use in the MK 16 Mod 1 Underwater Breathing Apparatus Rubicon Repository ID#: 123456789/3466 We have more like these on hand but lack of funds and time will be a limiting fcactor on when we can get to them. There are also reviews of failures in most evaluations done on different systems (Several in the Repository already). Slightly off topic but interesting on recording of O2 sensor data. DESIGN OF AN UNDERWATER TELEMETRIC SYSTEM FOR REBREATHERS Rubicon Repository ID#: 123456789/3715 abstract Interesting - I am using the R10 DS cells which have a faster response time but ar magnetic (i assume) I went for a dip on the w/e and all the cells were working fine and calibrated perfectly - then suddenly without any warning one of the cells just went tits up and died - measured it on the surface and it is at 3mV instead of the usual 21- 24mv like the others. Any ideas?? They are less that one year old. Steve
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7th November 2006, 12:11	#12 (permalink)
Scubascooby Better Off Out of the EU Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Nov 2005 Location: Great Britain Posts: 388	Re: O2 sensors - What you DON'T KNOW - FAILURE! Quote: (Originally Posted by sabgia) One CL is below upstream of sensors, the other is below but downstream thus balancing the pressure. The cells don't carry any pressure on the Meg! I have experience with 6 Teledyne R22's. 1 lasted 1 week, 2 about 6 months, 1 operates still after more than a year. The other two are about 4 months old and going good. I don't know the internal of the Meg but does the o-ring of the cell prevent gas passing to the rear of the cell ? Put another way, how is pressure equalised across the cell ? Peter __________________ "dove" is NOT the past tense of "dive" Better off OUT of the EU ! www.hugsac.org.uk
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7th November 2006, 12:27	#13 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: O2 sensors - What you DON'T KNOW - FAILURE! Quote: (Originally Posted by Scubascooby) ...Put another way, how is pressure equalised across the cell ? Thru the sorb. The sensor body is on the exhalation side, the sensor face is on the inhalation side (from reading the ANDI Meg manual). __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
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7th November 2006, 12:47	#14 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,100	Re: O2 sensors - What you DON'T KNOW - FAILURE! due to grammatical errors in the "report" it is difficult to determine if the failure report was directed to the diver or to the manufacturing process. It seemed that the analyst was telling his boss in the report "I told you molding those cases was going to come back and bite you" Does anyone know if there are multiple part numbers for this sensor, one being made with a molded cell housing and one with a machined version? I seem to recall seeing some black sensors that looked machined, I know my current cells are molded due to the seam on them. __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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7th November 2006, 13:04	#15 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,100	Re: Rubicon Research Repository How about completly off topic Quote: (Originally Posted by Gene_Hobbs) Thank you for the post! Rubicon Research Repository Evaluation of Analytical Industries Inc. Model Number PSR-11-33-NM Oxygen Sensors for Use With the MK 16 MOD 1 Underwater Breathing Apparatus Rubicon Repository ID#: 123456789/3536 Unmanned Test and Evaluation of the Teledyne Analytical Instruments R-10DN Oxygen Sensor for Use in the MK 16 Mod 1 Underwater Breathing Apparatus Rubicon Repository ID#: 123456789/3466 We have more like these on hand but lack of funds and time will be a limiting fcactor on when we can get to them. There are also reviews of failures in most evaluations done on different systems (Several in the Repository already). Slightly off topic but interesting on recording of O2 sensor data. DESIGN OF AN UNDERWATER TELEMETRIC SYSTEM FOR REBREATHERS Rubicon Repository ID#: 123456789/3715 abstract wow gene, thanks for the short game of pursuing the wild foul, how about posting something relevant next time. For those of us who may not want to register with the "RUBICON Foundation", NEDU has this same report here, but I warn you, it has nothing to do with the current discussion. http://stinet.dtic.mil/cgi-bin/GetTR...c=GetTRDoc.pdf __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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7th November 2006, 13:45	#16 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 711	Re: O2 sensors - What you DON'T KNOW - FAILURE! Ron, Didn’t Alex have a thread were he talked about the problems with design, contamination of the electrolyte and quality control issues? He broke it down on a study they did to check the practical issues and problems with the sensor design. The only black sensors I have seen were the Analytical Industries materials. Not sure how they were made. However, the fallout rate seems better by some people’s standards. Then again there are medical grade sensors- but the high output range is beyond the relative output of the R22 range. However, that does not require amplification. Please checkout this thread- http://www.rebreatherworld.com/gener...+contamination Nice posting on the hijack buddy- I hate having to register to see information that is in the public domain. Later, Andrew __________________ Howdy Senor- What’s Happening! Rob Davie April 2005- Presently in a state of transition from Open Circuit to Closed Circuit. "You will not be punished for your anger; you will be punished by it." - Buddha.
(Online)

7th November 2006, 14:51	#17 (permalink)
Scubascooby Better Off Out of the EU Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Nov 2005 Location: Great Britain Posts: 388	Re: O2 sensors - What you DON'T KNOW - FAILURE! Quote: (Originally Posted by decoweenie) Thru the sorb. The sensor body is on the exhalation side, the sensor face is on the inhalation side (from reading the ANDI Meg manual). That's interesting. So if the divers rolls from side to side there will be small pressure differences across the cell for a short period of time. Not enough to cause damage to the cell body I would imagine. __________________ "dove" is NOT the past tense of "dive" Better off OUT of the EU ! www.hugsac.org.uk
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7th November 2006, 15:44	#18 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,100	Re: O2 sensors - What you DON'T KNOW - FAILURE! Quote: (Originally Posted by Scubascooby) That's interesting. So if the divers rolls from side to side there will be small pressure differences across the cell for a short period of time. Not enough to cause damage to the cell body I would imagine. Not likely, or likely not measurable, the points are at isobaric levels but the gas can easily equalize pressure through the scrubber stack. you are making an assumption based on an assumption, the first post on differential pressure was inaccurate also. Good eye andrew, I remember that post, its a good read. __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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7th November 2006, 18:01	#19 (permalink)
Danil Meg Diver Current Rebreather/s: Megalodon Other Rebreather/s: Not Bought Yet Join Date: Apr 2005 Location: Karlstad, Sweden Posts: 110	Re: O2 sensors - What you DON'T KNOW - FAILURE! OK, the ONLY time you have a mesurable pressure difference on the cells in the MEG is when you test the sensor carriage assembly for loop integrety in your predive checks. But, it´s kind of fun reading other folks assumptions... __________________ -------------------- Dan Nilsson, Meg 67
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7th November 2006, 21:16	#20 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: O2 sensors - What you DON'T KNOW - FAILURE! Quote: (Originally Posted by Scubascooby) I don't know the internal of the Meg but does the o-ring of the cell prevent gas passing to the rear of the cell ? Put another way, how is pressure equalised across the cell ? Peter The front and back of the cells are connected throgh the sorb. Thus the only pressure the cells experience is the drop across the sorb. As mentioned by Dan above, a pressure-drop exists only when its tested for loop integrity! Earlier posts (that were incorrect) deleted. __________________ Gilles http://www.dirrebreather.com Last edited by Gilles : 8th November 2006 at 22:15.
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