Anyone used Megalodon-specific PSR-11-39-MHD sensor?

teksimple · 20th April 2007, 08:53

Anyone used this sensor? Would very much like to know if any Meg diver has, and what you thought of it.

It is the first sensor from AII that I sell, that I have yet to test. Main reason is that I don't have a Megalodon.

These are the R-22D replacement sensors that have voltage characteristics specified for the Megalodon.

DonalWalsh · 20th April 2007, 11:11

I haven't seen this before. Can you explain how exactly using this sensor benefits me? thanks

***jradomski*** · 20th April 2007, 12:47

Quote: (Originally Posted by teksimple)

Anyone used this sensor? Would very much like to know if any Meg diver has, and what you thought of it.

It is the first sensor from AII that I sell, that I have yet to test. Main reason is that I don't have a Megalodon.

These are the R-22D replacement sensors that have voltage characteristics specified for the Megalodon.

I have used the MHD cells in a HH successfully.. I prefer them over the MD cells because they give a bit more guaranteed margin.. I would hate to have a spare in my box only to find out it only 8.5mv which leave little margin on a HH..

Paul Evans · 20th April 2007, 12:56

Quote: (Originally Posted by jradomski)

I have used the MHD cells in a HH successfully.. I prefer them over the MD cells because they give a bit more guaranteed margin.. I would hate to have a spare in my box only to find out it only 8.5mv which leave little margin on a HH..

Can you explain the problems with the HH?

***jradomski*** · 20th April 2007, 13:45

Quote: (Originally Posted by Paul Evans)

Can you explain the problems with the HH?

What do you mean by problems??

Paul Evans · 20th April 2007, 14:14

Quote: (Originally Posted by jradomski)

What do you mean by problems??

Sorry that was a very bad way of putting it

What are the concerns over Margin between the different cells?

gibbogeo · 20th April 2007, 14:55

Quote: (Originally Posted by Paul Evans)

Sorry that was a very bad way of putting it

What are the concerns over Margin between the different cells?

If a cell is giving less than 40 mV in oxygen is not calibrated and is signaled as not working.

If you have low mv output in air, it is not sure you will have always more than 40 mV in oxygen.

***jradomski*** · 20th April 2007, 16:57

Quote: (Originally Posted by Paul Evans)

Sorry that was a very bad way of putting it

What are the concerns over Margin between the different cells?

A cell that meets the spec of 8.5 mv in air, if calibrated properly and in 100% oxygen will be approximately 40.6 mv.. That does not leave alot of room for cell drop off.. at 99% o2 its down to 40.2.. If you don't do a perfect flush it probably wount calibrate..

The HH requires that the mv reading be at least 40mv to calibrate..

dgschott · 20th April 2007, 22:26

I have been using one PSR-11-39-MHD cell and two Teledynes on my Meg (APECS 2)... The AI seems to react faster and better when moist, especially on long dives. There's nothing scientific about that, but it's been working well and something I have noticed. I'll eventually move the other Teledyne cells to the PSR-11-39-MHD.

Gilles · 20th April 2007, 23:44

Quote: (Originally Posted by jradomski)

The HH requires that the mv reading be at least 40mv to calibrate..

That seems a strange design feature. Does it really serve a purpose? I have observed cells that respond linearly and fine to just under 40mV. I have also had cells go non-linear (nominal voltage ~9.5) above 40mV and decided to trash them (whilst continuing use of afore-mentioned low voltage ones because they respond predictably).

Does low nominal cell voltage imply poor cell quality? Some new ones sometimes come out with low volts, but seem to work fine and for a long time.

Quote: (Originally Posted by dgschott)

I have been using one PSR-11-39-MHD cell and two Teledynes on my Meg (APECS 2)... The AI seems to react faster and better when moist, especially on long dives. There's nothing scientific about that, but it's been working well and something I have noticed. I'll eventually move the other Teledyne cells to the PSR-11-39-MHD.

That does it, next batch of cells are AI's.

20th April 2007, 08:53	#1 (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	Anyone used Megalodon-specific PSR-11-39-MHD sensor? Anyone used this sensor? Would very much like to know if any Meg diver has, and what you thought of it. It is the first sensor from AII that I sell, that I have yet to test. Main reason is that I don't have a Megalodon. These are the R-22D replacement sensors that have voltage characteristics specified for the Megalodon. __________________ ---- _____________ "I don't know the percentage of the Internet that's valid, do you? Jesus, it's scary." - Hunter S. Thompson
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20th April 2007, 11:11	#2 (permalink)
DonalWalsh Third Class Snorkeller Current Rebreather/s: Megalodon Other Rebreather/s: Evolution Join Date: Nov 2005 Location: Moving to London in Sept.....which way to the South Coast?? Posts: 133	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? I haven't seen this before. Can you explain how exactly using this sensor benefits me? thanks __________________ "Anybody can be a bum. All you need is the right girl, the right bar, and the right friends. They will see you off. They will christen your dumpster for you. "- Bill Hicks
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20th April 2007, 12:47	#3 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,011	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by teksimple) Anyone used this sensor? Would very much like to know if any Meg diver has, and what you thought of it. It is the first sensor from AII that I sell, that I have yet to test. Main reason is that I don't have a Megalodon. These are the R-22D replacement sensors that have voltage characteristics specified for the Megalodon. I have used the MHD cells in a HH successfully.. I prefer them over the MD cells because they give a bit more guaranteed margin.. I would hate to have a spare in my box only to find out it only 8.5mv which leave little margin on a HH.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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20th April 2007, 12:56	#4 (permalink)
Paul Evans Freedom is the Key. Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Oct 2006 Location: London Posts: 135	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by jradomski) I have used the MHD cells in a HH successfully.. I prefer them over the MD cells because they give a bit more guaranteed margin.. I would hate to have a spare in my box only to find out it only 8.5mv which leave little margin on a HH.. Can you explain the problems with the HH? __________________ "Freedom is what you do with what's been done to you." Jean-Paul Sartre "Any time anyone says, 'there is only one right way to do this' your bullshit meter should be pegged. Its a presumptive statement, made by a person who fears being proved wrong." Bill Gavin.
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20th April 2007, 13:45	#5 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,011	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by Paul Evans) Can you explain the problems with the HH? What do you mean by problems?? __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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20th April 2007, 14:14	#6 (permalink)
Paul Evans Freedom is the Key. Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Oct 2006 Location: London Posts: 135	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by jradomski) What do you mean by problems?? Sorry that was a very bad way of putting it What are the concerns over Margin between the different cells? __________________ "Freedom is what you do with what's been done to you." Jean-Paul Sartre "Any time anyone says, 'there is only one right way to do this' your bullshit meter should be pegged. Its a presumptive statement, made by a person who fears being proved wrong." Bill Gavin.
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20th April 2007, 14:55	#7 (permalink)
gibbogeo Gilberto Bonaga, Italy Current Rebreather/s: Classic Kiss Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Sep 2005 Location: italy Posts: 315	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by Paul Evans) Sorry that was a very bad way of putting it What are the concerns over Margin between the different cells? If a cell is giving less than 40 mV in oxygen is not calibrated and is signaled as not working. If you have low mv output in air, it is not sure you will have always more than 40 mV in oxygen.
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20th April 2007, 16:57	#8 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,011	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by Paul Evans) Sorry that was a very bad way of putting it What are the concerns over Margin between the different cells? A cell that meets the spec of 8.5 mv in air, if calibrated properly and in 100% oxygen will be approximately 40.6 mv.. That does not leave alot of room for cell drop off.. at 99% o2 its down to 40.2.. If you don't do a perfect flush it probably wount calibrate.. The HH requires that the mv reading be at least 40mv to calibrate.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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20th April 2007, 22:26	#9 (permalink)
dgschott Liquid Productions, LLC Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2005 Location: Aston, PA Posts: 115	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? I have been using one PSR-11-39-MHD cell and two Teledynes on my Meg (APECS 2)... The AI seems to react faster and better when moist, especially on long dives. There's nothing scientific about that, but it's been working well and something I have noticed. I'll eventually move the other Teledyne cells to the PSR-11-39-MHD. __________________ David Schott Liquid Productions, LLC
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20th April 2007, 23:44	#10 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: Anyone used Megalodon-specific PSR-11-39-MHD sensor? Quote: (Originally Posted by jradomski) The HH requires that the mv reading be at least 40mv to calibrate.. That seems a strange design feature. Does it really serve a purpose? I have observed cells that respond linearly and fine to just under 40mV. I have also had cells go non-linear (nominal voltage ~9.5) above 40mV and decided to trash them (whilst continuing use of afore-mentioned low voltage ones because they respond predictably). Does low nominal cell voltage imply poor cell quality? Some new ones sometimes come out with low volts, but seem to work fine and for a long time. Quote: (Originally Posted by dgschott) I have been using one PSR-11-39-MHD cell and two Teledynes on my Meg (APECS 2)... The AI seems to react faster and better when moist, especially on long dives. There's nothing scientific about that, but it's been working well and something I have noticed. I'll eventually move the other Teledyne cells to the PSR-11-39-MHD. That does it, next batch of cells are AI's. __________________ Gilles http://www.dirrebreather.com
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