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This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C27C4F.B8E04000 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit We ran concurrent experiments using different gasses. Bill Mee did heliox, JJ did trimix with all trimix deco gases, I did trimix with helium only in the deeper gasses. We were looking for advantages or disadvantages. What we found is that Bill Mee got the fastest and cleanest deco. I had no issues with my gas. JJ got an improvement over using my gases. We use as much helium as we can conveniently get in all gases. Our only rule is the minimum helium for gases used to dive ( as opposed to decompressing - 35 minimum vs 25 for the 120 deco gas ). We have minimum standard gasses as well as to helium, maximum an optimal PPO2s, and standard oxygen percentages for deco gases. You are taking the term "air break" literally. The intent of the term is to get as close to a normoxic PPO2 as possible for breaks, which is generally going to be your deepest gas, which is by definition going to be helium based in the WKPP. We do not dive air for anything, we do not dive nitrox for anything ( but we do decompress on it). Obviously, the guys with Haskel pumps can get to pure heliox or whatever they want. I generally keep mine a little on the high side for two reasons: one, it makes the stage bottles neutral, and two, it is a better gas. However, I have to drive 24 miles to pick up helium, so Haskel all the leftovers back on top of my doubles, and I eventually end up with heliox. I have a large compressor and a Haskel, so I don't have to deal with the usual nonsense. Just a side note - the couterdiffusion thing is BS. It is like all the other deco bs - designed to explain why people who should not be diving get bent, or in the case of couterdiffusion, why pigs get skin bends, but then that is merely for people who have never seen bacon and don't know how ludicrous this really is. -----Original Message----- From: Richard Waring [mailto:newkitric.hellsbells@vi*.ne*] Sent: Friday, October 25, 2002 3:32 AM To: techdiver Subject: Heliox While the list is quiet I have a question aimed mainly at Trey, I know one of your team uses heliox and wonder why you don't. On the same subject if I have dived heliox back to 6 meters and switch to pure o2 am I better off braking on to air or going back to helix I know there is a problem with counter diffusion if I use air but don't understand the full implications. Ric Waring ------=_NextPart_000_0014_01C27C4F.B8E04000 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 5.50.4728.2300" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>We ran=20 concurrent experiments using different gasses. Bill Mee did heliox, JJ = did=20 trimix with all trimix deco gases, I did trimix with helium only in the = deeper=20 gasses. We were looking for advantages or disadvantages. = </FONT></SPAN></DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>What=20 we found is that Bill Mee got the fastest and cleanest deco. I had no = issues=20 with my gas. JJ got an improvement over using my = gases.</FONT></SPAN></DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>We use=20 as much helium as we can conveniently get in all gases. Our only rule is = the=20 minimum helium for gases used to dive ( as opposed to decompressing - 35 = minimum=20 vs 25 for the 120 deco gas ). We have minimum standard gasses as well as = to=20 helium, maximum an optimal PPO2s, and standard oxygen percentages for = deco=20 gases.</FONT></SPAN></DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>You=20 are taking the term "air break" literally. The intent of the term is to = get as=20 close to a normoxic PPO2 as possible for breaks, which is generally = going to be=20 your deepest gas, which is by definition going to be helium based in the = WKPP.=20 We do not dive air for anything, we do not dive nitrox for anything ( = but we do=20 decompress on it).</FONT></SPAN></DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>Obviously, the guys with Haskel pumps can get to pure heliox or = whatever=20 they want. I generally keep mine a little on the high side for two = reasons: one,=20 it makes the stage bottles neutral, and two, it is a better gas. = However, I have=20 to drive 24 miles to pick up helium, so Haskel all the leftovers = back on=20 top of my doubles, and I eventually end up with heliox. I have a = large=20 compressor and a Haskel, so I don't have to deal with the usual=20 nonsense.</FONT></SPAN></DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D653191721-25102002><FONT face=3DArial color=3D#0000ff = size=3D2>Just a=20 side note - the couterdiffusion thing is BS. It is like all the other = deco bs -=20 designed to explain why people who should not be diving get bent, or in = the case=20 of couterdiffusion, why pigs get skin bends, but then that is merely for = people=20 who have never seen bacon and don't know how ludicrous this really=20 is.</FONT></SPAN></DIV> <BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px"> <DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT = face=3DTahoma=20 size=3D2>-----Original Message-----<BR><B>From:</B> Richard Waring=20 [mailto:newkitric.hellsbells@vi*.ne*]<BR><B>Sent:</B> Friday, = October 25,=20 2002 3:32 AM<BR><B>To:</B> techdiver<BR><B>Subject:</B>=20 Heliox<BR><BR></FONT></DIV> <DIV><FONT face=3DArial size=3D2>While the list is quiet I have a = question aimed=20 mainly at Trey, I know one of your team uses heliox and wonder why you = don't.=20 On the same subject if I have dived heliox back to 6 meters and switch = to pure=20 o2 am I better off braking on to air or going back to helix I know = there is a=20 problem with counter diffusion if I use air but don't understand the = full=20 implications. Ric Waring</FONT></DIV></BLOCKQUOTE></BODY></HTML> ------=_NextPart_000_0014_01C27C4F.B8E04000-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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