Handsets disagree on MV values

MarcLaukien · 3rd September 2007, 13:26

Quote: (Originally Posted by trob09)

Both. In my note to Kevin I suggested that it was a software thing. As I say, I am pretty confident that it's not the cells as I got the exact same behavior from 3 sets of cells.

If it's a software problem, then wouldn't everybody with the new handsets see this behavior?

***jradomski*** · 3rd September 2007, 13:27

Quote: (Originally Posted by trob09)

Are these the new Delrin handsets? I ask because I had sent Kevin a note on Saturday asking about similar behavior from my new handsets.

Flush O2 & get 48 - 52 mv, calibrate
Remove O2 Source (I have a meg & use the head calibration kit) watch MV drop to 9-11 range. PO2 in air? .25/.23/.21 Move wires around (i.e. plug wire for cell 1 into cell 3) and still get .25/.23/.21 put in different cells (some new, some old) and still get .25/.23./21

Put the same cells in my spare head with metal handsets - get .21/.20/.21.

I haven't heard back from Kevin (it's a holiday weekend and all), but I'm pretty confident that it's not the cell's non-linear performance.

Are you using the standard calibration mode or the "altitude" mode where it takes ambient pressure into account..

**trob09** · 3rd September 2007, 13:34

Quote: (Originally Posted by jradomski)

Are you using the standard calibration mode or the "altitude" mode where it takes ambient pressure into account..

Standard calibration

**trob09** · 3rd September 2007, 13:35

Quote: (Originally Posted by MarcLaukien)

If it's a software problem, then wouldn't everybody with the new handsets see this behavior?

Dunno. some people have problems with WinXP, others don't.

n2diving · 4th September 2007, 01:32

Try using the bag method of calibration on the head. I've seen it get rid of that slight non-linear behavior...

P02 · 27th September 2007, 15:40

Quote: (Originally Posted by trob09)

Are these the new Delrin handsets? I ask because I had sent Kevin a note on Saturday asking about similar behavior from my new handsets.

Flush O2 & get 48 - 52 mv, calibrate
Remove O2 Source (I have a meg & use the head calibration kit) watch MV drop to 9-11 range. PO2 in air? .21/.25/.23 Move wires around (i.e. plug wire for cell 1 into cell 3) and still get .21/.25/.23 put in different cells (some new, some old) and still get .21/.25/.23

Put the same cells in my spare head with metal handsets - get .21/.20/.21.

I haven't heard back from Kevin (it's a holiday weekend and all), but I'm pretty confident that it's not the cell's non-linear performance.

Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing ....

**trob09** · 27th September 2007, 15:47

Quote: (Originally Posted by P02)

Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing ....

I did.

It turns out to not be an issue with the HammerHead but rather an issue with the Teledyne R22d Cells I have. I replaced them with AII cells and after a few days of air acclimatization i am getting readings as expected. Interestingly, MV readings are slightly higher than I am used to with the Teledyne cells - 13mv in air instead of 10~11, 60mv in O2 instead of 48~50.

Kevin was very responsive and thorough in helping to troubleshoot the issue.

T

MarcLaukien · 27th September 2007, 15:47

Quote: (Originally Posted by P02)

Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing ....

I can't speak for trob09, but I had a good email exchange about this with Kevin. He told me that all units are tested with a millivolt generator before delivery. To be on the safe side, he offered me to send back the units for an additional check-up with a millivolt generator. I just sent mine a few days ago, so let's see what the results will be.

P02 · 27th September 2007, 19:56

Quote: (Originally Posted by trob09)

I did.

It turns out to not be an issue with the HammerHead but rather an issue with the Teledyne R22d Cells I have. I replaced them with AII cells and after a few days of air acclimatization i am getting readings as expected. Interestingly, MV readings are slightly higher than I am used to with the Teledyne cells - 13mv in air instead of 10~11, 60mv in O2 instead of 48~50.

Kevin was very responsive and thorough in helping to troubleshoot the issue.

T

Im happy to hear its not the HH, it will help me sleep better - maybe Im missing something here but how does it explain that you moved around the cells and still got the same readings ? The variance should have "moved" with the cells ? Or are R22d's not compatible with the units somehow.... ? Is the conlusion that you should stay away from R22d 's ?

**trob09** · 27th September 2007, 20:45

Quote: (Originally Posted by P02)

Im happy to hear its not the HH, it will help me sleep better - maybe Im missing something here but how does it explain that you moved around the cells and still got the same readings ? The variance should have "moved" with the cells ? Or are R22d's not compatible with the units somehow.... ? Is the conlusion that you should stay away from R22d 's ?

I don't know why moving them around didn't do anything. That part's a mystery. I do know that it has gone away with the AII cells. If I move the wires on these, the numbers move.

It's hard for me to say "stay away from r22d's" they've always been solid performers for me in the past.

T

3rd September 2007, 13:26	#11 (permalink)
MarcLaukien Custom Title Allowed! Current Rebreather/s: Other CCR Other Rebreather/s: Optima Other CCR Join Date: Dec 2006 Location: South East Florida Posts: 202	Re: Handsets disagree on MV values Quote: (Originally Posted by trob09) Both. In my note to Kevin I suggested that it was a software thing. As I say, I am pretty confident that it's not the cells as I got the exact same behavior from 3 sets of cells. If it's a software problem, then wouldn't everybody with the new handsets see this behavior?
(Online)

3rd September 2007, 13:27	#12 (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: 2,998	Re: Handsets disagree on MV values Quote: (Originally Posted by trob09) Are these the new Delrin handsets? I ask because I had sent Kevin a note on Saturday asking about similar behavior from my new handsets. Flush O2 & get 48 - 52 mv, calibrate Remove O2 Source (I have a meg & use the head calibration kit) watch MV drop to 9-11 range. PO2 in air? .25/.23/.21 Move wires around (i.e. plug wire for cell 1 into cell 3) and still get .25/.23/.21 put in different cells (some new, some old) and still get .25/.23./21 Put the same cells in my spare head with metal handsets - get .21/.20/.21. I haven't heard back from Kevin (it's a holiday weekend and all), but I'm pretty confident that it's not the cell's non-linear performance. Are you using the standard calibration mode or the "altitude" mode where it takes ambient pressure into account.. __________________ 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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3rd September 2007, 13:34	#13 (permalink)
trob09 . Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Posts: 704	Re: Handsets disagree on MV values Quote: (Originally Posted by jradomski) Are you using the standard calibration mode or the "altitude" mode where it takes ambient pressure into account.. Standard calibration
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3rd September 2007, 13:35	#14 (permalink)
trob09 . Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Posts: 704	Re: Handsets disagree on MV values Quote: (Originally Posted by MarcLaukien) If it's a software problem, then wouldn't everybody with the new handsets see this behavior? Dunno. some people have problems with WinXP, others don't.
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4th September 2007, 01:32	#15 (permalink)
n2diving Custom Title Allowed! Current Rebreather/s: Optima Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Feb 2005 Location: Florida, USA Posts: 271	Re: Handsets disagree on MV values Try using the bag method of calibration on the head. I've seen it get rid of that slight non-linear behavior...
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27th September 2007, 15:40	#16 (permalink)
P02 New Member Current Rebreather/s: Optima Other Rebreather/s: Optima Join Date: Jan 2007 Location: Ljungsbro_Sweden Posts: 18	Re: Handsets disagree on MV values Quote: (Originally Posted by trob09) Are these the new Delrin handsets? I ask because I had sent Kevin a note on Saturday asking about similar behavior from my new handsets. Flush O2 & get 48 - 52 mv, calibrate Remove O2 Source (I have a meg & use the head calibration kit) watch MV drop to 9-11 range. PO2 in air? .21/.25/.23 Move wires around (i.e. plug wire for cell 1 into cell 3) and still get .21/.25/.23 put in different cells (some new, some old) and still get .21/.25/.23 Put the same cells in my spare head with metal handsets - get .21/.20/.21. I haven't heard back from Kevin (it's a holiday weekend and all), but I'm pretty confident that it's not the cell's non-linear performance. Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing ....
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27th September 2007, 15:47	#17 (permalink)
trob09 . Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Posts: 704	Re: Handsets disagree on MV values Quote: (Originally Posted by P02) Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing .... I did. It turns out to not be an issue with the HammerHead but rather an issue with the Teledyne R22d Cells I have. I replaced them with AII cells and after a few days of air acclimatization i am getting readings as expected. Interestingly, MV readings are slightly higher than I am used to with the Teledyne cells - 13mv in air instead of 10~11, 60mv in O2 instead of 48~50. Kevin was very responsive and thorough in helping to troubleshoot the issue. T
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27th September 2007, 15:47	#18 (permalink)
MarcLaukien Custom Title Allowed! Current Rebreather/s: Other CCR Other Rebreather/s: Optima Other CCR Join Date: Dec 2006 Location: South East Florida Posts: 202	Re: Handsets disagree on MV values Quote: (Originally Posted by P02) Did you get some answers to this problem from kevin .. ? I must say, it looks most disturbing .... I can't speak for trob09, but I had a good email exchange about this with Kevin. He told me that all units are tested with a millivolt generator before delivery. To be on the safe side, he offered me to send back the units for an additional check-up with a millivolt generator. I just sent mine a few days ago, so let's see what the results will be.
(Online)

27th September 2007, 19:56	#19 (permalink)
P02 New Member Current Rebreather/s: Optima Other Rebreather/s: Optima Join Date: Jan 2007 Location: Ljungsbro_Sweden Posts: 18	Re: Handsets disagree on MV values Quote: (Originally Posted by trob09) I did. It turns out to not be an issue with the HammerHead but rather an issue with the Teledyne R22d Cells I have. I replaced them with AII cells and after a few days of air acclimatization i am getting readings as expected. Interestingly, MV readings are slightly higher than I am used to with the Teledyne cells - 13mv in air instead of 10~11, 60mv in O2 instead of 48~50. Kevin was very responsive and thorough in helping to troubleshoot the issue. T Im happy to hear its not the HH, it will help me sleep better - maybe Im missing something here but how does it explain that you moved around the cells and still got the same readings ? The variance should have "moved" with the cells ? Or are R22d's not compatible with the units somehow.... ? Is the conlusion that you should stay away from R22d 's ?
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27th September 2007, 20:45	#20 (permalink)
trob09 . Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Posts: 704	Re: Handsets disagree on MV values Quote: (Originally Posted by P02) Im happy to hear its not the HH, it will help me sleep better - maybe Im missing something here but how does it explain that you moved around the cells and still got the same readings ? The variance should have "moved" with the cells ? Or are R22d's not compatible with the units somehow.... ? Is the conlusion that you should stay away from R22d 's ? I don't know why moving them around didn't do anything. That part's a mystery. I do know that it has gone away with the AII cells. If I move the wires on these, the numbers move. It's hard for me to say "stay away from r22d's" they've always been solid performers for me in the past. T
(Offline)

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