Doing my Nitrox cert through ANDI - Have a few questions

[5ata]

I'm in the process of completing my ANDI Nitrox cert and have some questions I hope can be answered. Please excuse what might be seen as n00b questions but I'm primarily a freediver and normally eschew all the gear associated with tank diving.

1. Is it advisable to get a personal O2 analyzer to verify fills?
2. I have a Poseidon Cyklon reg and ODIN octo with Poseidon analog console and both Cressi Arcimede Nitrox ready dive computer and my Suunto D3 freedive computer which also does Nitrox as a backup - How would I find out if my regs are Nitrox ready? My local LDS isn't a Poseidon dealer.
3. I'm looking to get my first personal tank for Nitrox - I want to find the balance between lightweight and max dive time. Being a freediver, I love the idea of a low profile (double 40's seem ideal to me), but some seem to feel a single tank is just as viable. I want as low profile if single tank as I can get and I prefer DIN - any recommendations?

 

[k-valve]

Is it advisable to get a personal O2 analyzer to verify fills?

I have my own because it is more convenient. However, you should be able to verify your nitrox fills at the dive shop. In fact, some of them won't let you take the tanks without verifying the mix and signing off on them.

I have a Poseidon Cyklon reg and ODIN octo with Poseidon analog console and both Cressi Arcimede Nitrox ready dive computer and my Suunto D3 freedive computer which also does Nitrox as a backup - How would I find out if my regs are Nitrox ready? My local LDS isn't a Poseidon dealer.

You can go online and check the Poseidon and Cressi websites to see if those models ship nitrox ready, but you probably should think about getting them O2 cleaned if you've used them a lot and don't know the quality of air that's been run through them...or if you bought them second hand.

I'm looking to get my first personal tank for Nitrox - I want to find the balance between lightweight and max dive time. Being a freediver, I love the idea of a low profile (double 40's seem ideal to me), but some seem to feel a single tank is just as viable. I want as low profile if single tank as I can get and I prefer DIN - any recommendations?

I've never dove double 80's but I know several people who like them. High pressure steel tanks are pretty streamlined too, so you may want to look into that option.

 

[The Kraken]

5ata,

Some good answers above.

As to the tank, check out the HP 100's. 7.25" diameter and are about 5" shorter than an aluminum 80.

the K

 

[uncleavi]

I used to be an ANDI Instructor and there is nothing wrong with having your own 02 analyzer.
ANDI will want you to have any gear that is exposed to more than 23% 02 your gear should be 02 cleaned. I have spoken to Ed Betts the head of ANDI and also to Dick Rutkowski who is the man who brought nitrox to the recreational dive world and he along with most diviers belive that if your gear is used with 40% 02 or less than it's ok as it is. But, if your tank is exposed to pure 02 in it's filling then you need it to be 02 cleaned.

 

[padiscubapro]

I'm in the process of completing my ANDI Nitrox cert and have some questions I hope can be answered. Please excuse what might be seen as n00b questions but I'm primarily a freediver and normally eschew all the gear associated with tank diving.

1. Is it advisable to get a personal O2 analyzer to verify fills?
2. I have a Poseidon Cyklon reg and ODIN octo with Poseidon analog console and both Cressi Arcimede Nitrox ready dive computer and my Suunto D3 freedive computer which also does Nitrox as a backup - How would I find out if my regs are Nitrox ready? My local LDS isn't a Poseidon dealer.
3. I'm looking to get my first personal tank for Nitrox - I want to find the balance between lightweight and max dive time. Being a freediver, I love the idea of a low profile (double 40's seem ideal to me), but some seem to feel a single tank is just as viable. I want as low profile if single tank as I can get and I prefer DIN - any recommendations?

ANDI follows the cga and almost all governmental agencies world wide in that if you expose gear to greater than about 23% you should treat it as oxygen..

at percentages used by recreational divers the chance of an oxygen fire is unlikely but partial combustion is definately a possibility.. most times you would never know and you breathed in alot of co and possibly other poisoness gases..

if the reg is sold as nitrox ready (2 or the 3 xtreme regs are sold that way), then to keep it that way you must use only oxygen compatible gases whether it be air or nitrox. Tanks/valves used for partial pressure blending must always be kept oxygen clean..

I have seen many regs that people complained that the performance was not right or the ip creeping... Many of these regs showed evidence of partial combustion..

Another thing to consider is that contaminents are cumulative, so initially using non oxygen compatible air probably isnt an issue but the longer you use dirty air the higher the risk becomes.. two areas in particular are the scintered filter and the high pressure seat..

 

[h90]

Is that just up to 40 %?
If yes: own analyzer can't be wrong, but to borrow one in the dive shop might be cheaper. Always good to use a different analyzer that the guy who filled it.

Almost all(if not all) gears can handle 40 %.
For the tank the only thing is partial pressure blending, than it must be oxygen clean, else not.