Always analyze your gas!

General banter about diving and why we love it.
Post Reply
User avatar
LCF
I've Got Gills
Posts: 5697
Joined: Tue May 30, 2006 5:05 pm

Always analyze your gas!

Post by LCF » Tue May 14, 2013 10:37 am

"Sometimes, when your world is going sideways, the second best thing to everything working out right, is knowing you are loved..." ljjames

User avatar
Tom Nic
I've Got Gills
Posts: 9342
Joined: Mon Apr 10, 2006 6:26 pm

Re: Always analyze your gas!

Post by Tom Nic » Tue May 14, 2013 11:24 am

Thanks for sharing - good reminder!

And oddly enough, in this case a CCR was more safe than open circuit would have been because of the alarms and constant PO2 reading in the loop that an open circuit diver would NOT have had.
More Pics Than You Have Time To Look AT
"Anyone who thinks this place is over moderated is bat-crazy anarchist." -Ben, Airsix
"Warning: No dive masters are going to be there, Just a bunch of old fat guys taking pictures of fish." -Bassman

User avatar
Joshua Smith
I've Got Gills
Posts: 10228
Joined: Mon Apr 03, 2006 9:32 pm

Re: Always analyze your gas!

Post by Joshua Smith » Tue May 14, 2013 11:40 am

LCF wrote:A sobering report from the UK: http://www.thediveforum.com/i-learned-a ... stake.html


I cannot even remotely imagine doing what that guy did. He's lucky he survived.
Maritime Documentation Society

"To venture into the terrible loneliness, one must have something greater than greed. Love. One needs love for life, for intrigue, for mystery."

User avatar
CaptnJack
I've Got Gills
Posts: 7760
Joined: Fri Jul 07, 2006 2:29 pm

Re: Always analyze your gas!

Post by CaptnJack » Tue May 14, 2013 12:17 pm

Joshua Smith wrote:
LCF wrote:A sobering report from the UK: http://www.thediveforum.com/i-learned-a ... stake.html


I cannot even remotely imagine doing what that guy did. He's lucky he survived.


Ditto.
How could you not notice a ppO2 of 1.0 on proper prebreathe? Or "analyze gas" on a proper checklist? So many eff ups...
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.

User avatar
thefeve
Compulsive Diver
Posts: 361
Joined: Mon Jun 25, 2012 7:24 am

Re: Always analyze your gas!

Post by thefeve » Tue May 14, 2013 12:24 pm

wow, that's intense.

So it brings up the question, for many newer divers, or those that just rent tanks, etc - does everyone on here analyze their gas pre-dive? Seems like that is part of the "lessons learned" here, but it doesn't seem to me that most people are analyzing their tanks before gearing up.

Though he states and all would agree its the diver's response to know what gas your diving, its scary to me that the shop would fill a tank with the wrong thing... I guess i'm interested to know how many people on OC analyze every time they get fills...
I think you've figured out the root cause of your problems. Even sea lions get annoyed by splitfin divers silting out their dive sites. Switch back to your jets and you'll be safe from the sea lion silt prevention patrol from now on. - NWbrewer

User avatar
CaptnJack
I've Got Gills
Posts: 7760
Joined: Fri Jul 07, 2006 2:29 pm

Re: Always analyze your gas!

Post by CaptnJack » Tue May 14, 2013 12:28 pm

thefeve wrote:So it brings up the question, for many newer divers, or those that just rent tanks, etc - does everyone on here analyze their gas pre-dive? Seems like that is part of the "lessons learned" here, but it doesn't seem to me that most people are analyzing their tanks before gearing up.

Not at the dive site. I won't put a tank in the truck which hasn't been analyzed and labeled with %age mix, date, and that its been CO checked however. I won't put a reg on a tank which is missing a label.

thefeve wrote:Though he states and all would agree its the diver's response to know what gas your diving, its scary to me that the shop would fill a tank with the wrong thing... I guess i'm interested to know how many people on OC analyze every time they get fills...

Yes, unless its suit or boat inflation gas. I don't breath those, they can't kill me.
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.

User avatar
Dusty2
I've Got Gills
Posts: 6388
Joined: Wed Mar 21, 2007 9:04 pm

Re: Always analyze your gas!

Post by Dusty2 » Tue May 14, 2013 1:02 pm

The shop I use labels with mix and safe depth for 1.4ppo, I seldom check mine but then I always use the same shop and I know that the guys are tech divers and the tanks are always checked 100% There is no way I would trust a shop that I was not familiar with unless I actually watched them test it.

That shop is damn lucky. If this guy had not had a safe operating system and a bail out he wouldn't have survived and they would have been out of business. I guess you could say it's an honest mistake but no way in hell that bottle should have made it into the water. I mean how can it get through all the checks it should have had? Lucky guy everything went well. He could have just gone into convulsions and that would have been all she wrote.

User avatar
Jeff Pack
I've Got Gills
Posts: 2942
Joined: Mon Sep 12, 2011 8:51 am

Re: Always analyze your gas!

Post by Jeff Pack » Tue May 14, 2013 1:13 pm

On a rebreather, specific checklist items are always analyze your O2, dil, and bailout gases.

I never analyzed gases when I dove OC using shop fills (all mine were from Tacoma Scuba, who I trust implicitly), but now with my own compressor and 3 rebreathers, I consider it an outright requirement to analyze gas. I do fudge though that I don't analyze O2, once I've used/analysed that cylinder for filling O2 bottles, and I don't analyze if running straight air in my dil. But any mixes, I always analyze.
Last edited by Jeff Pack on Tue May 14, 2013 1:33 pm, edited 1 time in total.
=============================================

- I got a good squirt in my mouth
- I would imagine that there would be a large amount of involuntary gagging
- I don't know about you but I'm not into swallowing it

CCR discussion on Caustic Cocktails.

User avatar
CaptnJack
I've Got Gills
Posts: 7760
Joined: Fri Jul 07, 2006 2:29 pm

Re: Always analyze your gas!

Post by CaptnJack » Tue May 14, 2013 1:19 pm

Dusty2 wrote:The shop I use labels with mix and safe depth for 1.4ppo, I seldom check mine but then I always use the same shop and I know that the guys are tech divers and the tanks are always checked 100% There is no way I would trust a shop that I was not familiar with unless I actually watched them test it.

That shop is damn lucky. If this guy had not had a safe operating system and a bail out he wouldn't have survived and they would have been out of business. I guess you could say it's an honest mistake but no way in hell that bottle should have made it into the water. I mean how can it get through all the checks it should have had? Lucky guy everything went well. He could have just gone into convulsions and that would have been all she wrote.


Its the diver's responsibilty to analyze their gas, not the shop's. It doesn't matter who works there, analyze and label your own gas.

Minimum contents label includes O2 percentage (customarily to one decimal place), date, MOD, and initials. In a shop environment you should also be filling out a fill log with this information to confirm that YOU know what you picked up and its limitations.

I can't believe you guys are trusting anyone else on this issue. I fill all my own cylinders and I still analyze every one before putting it in the truck to go to a dive site.
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.

User avatar
Nwbrewer
I've Got Gills
Posts: 4521
Joined: Fri Jul 21, 2006 10:59 am

Re: Always analyze your gas!

Post by Nwbrewer » Tue May 14, 2013 1:28 pm

CaptnJack wrote:Yes, unless its suit or boat inflation gas. I don't breath those, they can't kill me.



Wouldn't want to put O2 in my boat! (Especially the rate ar which I've been know to fill it...
"Screw "annual" service,... I get them serviced when they break." - CaptnJack (paraphrased)


"you do realize you're supposed to mix the :koolaid: with water and drink it, not snort the powder directly from the packet, right? :smt064 " - Spatman

User avatar
kdupreez
I've Got Gills
Posts: 1724
Joined: Mon Apr 20, 2009 3:27 am

Re: Always analyze your gas!

Post by kdupreez » Tue May 14, 2013 1:31 pm

Whoa, this guy is lucky to be alive..

Good lesson.. I guess that's why actually checking millivolts on cells is a good idea.. My analyzer shows the millivolts during its calibration as well. Not sure how rebreather divers do this, but I'm guessing if this dude checked the millivolts displays on his dill pre-breathing, it would have spiked? Not a breather diver so no idea on the protocol.

So the question about analyze before dive. It depends on he situation, but at the very least I recommend people analyze twice and with different analyzers. If the one analyzer was screwed, you won't know if you analyze with the same analyzer as they used to fill.

When I pickup from a shop, I'll use their analyzer to verify the fill, but I will always analyze with my own analyzer before diving it, either the night before or just before the dive. It takes 30 seconds and can save your life.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.

When teaching GUE Fundies classes we require teams to analyze the day before, write the percentage and on the day of diving, analyze again and put down the one decimal point and date.. So labels without one decimal point is known to not have been analyzed twice.

It's a hard lesson to learn, but I have sent the entire team out of the water, back to their cars for one member who have not analyzed before diving it. After that everyone always makes sure that all gas have been analyzed and labeled.

It's just as much the buddy's responsibility to verify that everyone analyzed gas, as its your own responsibility. If we dive and my buddy says he didn't analyze, but it's ok, he trust the shop.. Out we go and go analyze..

People think this is overkill and roll their eyes.. Until the day something like above happens and you die because you skipped a 30 second step..

Complacency kills.. Short cuts kill.. Not a question of "if", but "when"
"I believe that if life gives you lemons, you should make lemonade... And try to find somebody whose life has given them vodka, and have a party" - Ron White

User avatar
Jeff Pack
I've Got Gills
Posts: 2942
Joined: Mon Sep 12, 2011 8:51 am

Re: Always analyze your gas!

Post by Jeff Pack » Tue May 14, 2013 1:41 pm

Sensor mv values are always tracked, every checklist has me writing down the mv of a cell at .21 and 1.0 (as well as age of sensors). I know pretty much the range a cell should be at in both ranges, and also have a cell checker for testing cells at pressure.
=============================================

- I got a good squirt in my mouth
- I would imagine that there would be a large amount of involuntary gagging
- I don't know about you but I'm not into swallowing it

CCR discussion on Caustic Cocktails.

User avatar
Jeff Pack
I've Got Gills
Posts: 2942
Joined: Mon Sep 12, 2011 8:51 am

Re: Always analyze your gas!

Post by Jeff Pack » Tue May 14, 2013 1:44 pm

and just to complicate things, you need to calibrate/check your analyzer too, which means having reference gas (In my case O2, 21% and 100% He).
=============================================

- I got a good squirt in my mouth
- I would imagine that there would be a large amount of involuntary gagging
- I don't know about you but I'm not into swallowing it

CCR discussion on Caustic Cocktails.

User avatar
thefeve
Compulsive Diver
Posts: 361
Joined: Mon Jun 25, 2012 7:24 am

Re: Always analyze your gas!

Post by thefeve » Tue May 14, 2013 2:22 pm

Thanks for the info and thoughts on this. Still being a relatively new diver, its something that wasn't really ingrained or pushed for me to do with fills. After this discussion though its definitely something I'll be paying closer attention to. I rarely use anything other than standard air, but habits are good to start early.

kdupreez wrote:.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.


Any reference to where/how this is done? This now has me thinking an analyzer should move to the top of my gear list...
I think you've figured out the root cause of your problems. Even sea lions get annoyed by splitfin divers silting out their dive sites. Switch back to your jets and you'll be safe from the sea lion silt prevention patrol from now on. - NWbrewer

User avatar
Nwbrewer
I've Got Gills
Posts: 4521
Joined: Fri Jul 21, 2006 10:59 am

Re: Always analyze your gas!

Post by Nwbrewer » Tue May 14, 2013 2:25 pm

thefeve wrote:Thanks for the info and thoughts on this. Still being a relatively new diver, its something that wasn't really ingrained or pushed for me to do with fills. After this discussion though its definitely something I'll be paying closer attention to. I rarely use anything other than standard air, but habits are good to start early.

kdupreez wrote:.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.


Any reference to where/how this is done? This now has me thinking an analyzer should move to the top of my gear list...


http://oxycheq.com/index.php?main_page= ... ucts_id=12
"Screw "annual" service,... I get them serviced when they break." - CaptnJack (paraphrased)


"you do realize you're supposed to mix the :koolaid: with water and drink it, not snort the powder directly from the packet, right? :smt064 " - Spatman

User avatar
CaptnJack
I've Got Gills
Posts: 7760
Joined: Fri Jul 07, 2006 2:29 pm

Re: Always analyze your gas!

Post by CaptnJack » Tue May 14, 2013 2:31 pm

Nwbrewer wrote:
thefeve wrote:Thanks for the info and thoughts on this. Still being a relatively new diver, its something that wasn't really ingrained or pushed for me to do with fills. After this discussion though its definitely something I'll be paying closer attention to. I rarely use anything other than standard air, but habits are good to start early.

kdupreez wrote:.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.


Any reference to where/how this is done? This now has me thinking an analyzer should move to the top of my gear list...


http://oxycheq.com/index.php?main_page= ... ucts_id=12


Spend the extra $19 on the "10 turn pot" FWIW. The default is a little cheaper but way too fiddly.
http://oxycheq.com/index.php?main_page= ... ucts_id=13

Sensors last about 30months, don't buy a spare until the first one dies.
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.

User avatar
kdupreez
I've Got Gills
Posts: 1724
Joined: Mon Apr 20, 2009 3:27 am

Re: Always analyze your gas!

Post by kdupreez » Tue May 14, 2013 3:31 pm

+1 on what Richard said.

That link from nwbrewer will work. I can also recommend Vance Harlow's "oxygen hackers companion"

They lay out the plans and all you ever wanted to know about nitrox blending and building your own DIY analyzer. I built 2 of these based on the book.


http://www.airspeedpress.com/newoxyhacker.html

That oxycheq one is a very convenient package at a very low premium for the kit.
"I believe that if life gives you lemons, you should make lemonade... And try to find somebody whose life has given them vodka, and have a party" - Ron White

User avatar
CaptnJack
I've Got Gills
Posts: 7760
Joined: Fri Jul 07, 2006 2:29 pm

Re: Always analyze your gas!

Post by CaptnJack » Tue May 14, 2013 3:58 pm

IMHO shops that sell nitrox should have everyone analyze their plain air fills too. Obviously, based on the vignette alone, something "other than air" could be put into a cylinder marked "air"...
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.

User avatar
LCF
I've Got Gills
Posts: 5697
Joined: Tue May 30, 2006 5:05 pm

Re: Always analyze your gas!

Post by LCF » Tue May 14, 2013 7:26 pm

We analyze all our gas before we breathe it. I have used shop analyzers, and I have no problem with it if the analyzer is giving me a number that is close to what it is supposed to be. Nowadays, we use our own analyzer. I do analyze air, if it came from a shop that pumps anything else on a regular basis. It's a quick, cheap test, and it could save your life.
"Sometimes, when your world is going sideways, the second best thing to everything working out right, is knowing you are loved..." ljjames

jerryehrlich
Avid Diver
Posts: 99
Joined: Mon Aug 25, 2008 10:34 am

Re: Always analyze your gas!

Post by jerryehrlich » Tue May 14, 2013 8:56 pm

CaptnJack wrote:
thefeve wrote:So it brings up the question, for many newer divers, or those that just rent tanks, etc - does everyone on here analyze their gas pre-dive? Seems like that is part of the "lessons learned" here, but it doesn't seem to me that most people are analyzing their tanks before gearing up.



thefeve wrote:Though he states and all would agree its the diver's response to know what gas your diving, its scary to me that the shop would fill a tank with the wrong thing... I guess i'm interested to know how many people on OC analyze every time they get fills...


Every time. PP my own fills and analyze at shop with shop analyzer. Test again before diving with my analyzer.

Jerry
Hoodsportndive

User avatar
pensacoladiver
I've Got Gills
Posts: 1350
Joined: Tue Aug 26, 2008 5:00 pm

Re: Always analyze your gas!

Post by pensacoladiver » Wed May 15, 2013 3:19 am

We had a tech instructor die recently in Florida on the Hydro Atlantic. I have not seen the official report, but the word is, he had his shop he works at fill the tanks with air.

Problem was, somehow, that air turned into 36 percent. He convulsed at approx 165 feet and died shortly thereafter at the hospital.

Analyze every tank no matter what the circumstances.

User avatar
loanwolf
Pelagic
Posts: 945
Joined: Mon Jan 07, 2008 7:20 am

Re: Always analyze your gas!

Post by loanwolf » Thu May 16, 2013 7:42 am

pensacoladiver wrote:We had a tech instructor die recently in Florida on the Hydro Atlantic. I have not seen the official report, but the word is, he had his shop he works at fill the tanks with air.

Problem was, somehow, that air turned into 36 percent. He convulsed at approx 165 feet and died shortly thereafter at the hospital.

Analyze every tank no matter what the circumstances.


I agree with this one. I have seen shops fill the wrong gas several times. Quite easy to do when they are banking nitrox and using the same fill whips as for air.

I have also seen people grab the wrong tank and dive nitrox when they thought they had air. also the other way around diving air when they thought they had the nitrox tank. So clearly marking you tanks is very important.

But you should still test it before the reg goes on.
Greg
Life is Short do as Much as Possible in as Short of Period of Time as Possible.

User avatar
Jeremy
I've Got Gills
Posts: 1541
Joined: Sat Jul 16, 2011 3:25 pm

Re: Always analyze your gas!

Post by Jeremy » Thu May 16, 2013 9:52 am

kdupreez wrote:Whoa, this guy is lucky to be alive..

Good lesson.. I guess that's why actually checking millivolts on cells is a good idea.. My analyzer shows the millivolts during its calibration as well. Not sure how rebreather divers do this, but I'm guessing if this dude checked the millivolts displays on his dill pre-breathing, it would have spiked? Not a breather diver so no idea on the protocol.

So the question about analyze before dive. It depends on he situation, but at the very least I recommend people analyze twice and with different analyzers. If the one analyzer was screwed, you won't know if you analyze with the same analyzer as they used to fill.

When I pickup from a shop, I'll use their analyzer to verify the fill, but I will always analyze with my own analyzer before diving it, either the night before or just before the dive. It takes 30 seconds and can save your life.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.

When teaching GUE Fundies classes we require teams to analyze the day before, write the percentage and on the day of diving, analyze again and put down the one decimal point and date.. So labels without one decimal point is known to not have been analyzed twice.

It's a hard lesson to learn, but I have sent the entire team out of the water, back to their cars for one member who have not analyzed before diving it. After that everyone always makes sure that all gas have been analyzed and labeled.

It's just as much the buddy's responsibility to verify that everyone analyzed gas, as its your own responsibility. If we dive and my buddy says he didn't analyze, but it's ok, he trust the shop.. Out we go and go analyze..

People think this is overkill and roll their eyes.. Until the day something like above happens and you die because you skipped a 30 second step..

Complacency kills.. Short cuts kill.. Not a question of "if", but "when"


First thing I bought after Fundies was an analyzer. :)

KneeDeep
Submariner
Posts: 568
Joined: Tue Sep 06, 2011 8:25 pm

Re: Always analyze your gas!

Post by KneeDeep » Thu May 16, 2013 11:32 am

CaptnJack wrote:
Nwbrewer wrote:
thefeve wrote:Thanks for the info and thoughts on this. Still being a relatively new diver, its something that wasn't really ingrained or pushed for me to do with fills. After this discussion though its definitely something I'll be paying closer attention to. I rarely use anything other than standard air, but habits are good to start early.

kdupreez wrote:.. And analyzers can be built for less than $100.. I have one in my compressor during filling and a different one in the truck for before diving.


Any reference to where/how this is done? This now has me thinking an analyzer should move to the top of my gear list...


http://oxycheq.com/index.php?main_page= ... ucts_id=12


Spend the extra $19 on the "10 turn pot" FWIW. The default is a little cheaper but way too fiddly.
http://oxycheq.com/index.php?main_page= ... ucts_id=13

Sensors last about 30months, don't buy a spare until the first one dies.

Have both of these on order :partydance:
The ocean is a lousy teacher. First you get a test, then the lesson.

Post Reply