<DIV style="font-family:Arial, sans-serif; font-size:10pt;"><DIV>Sean, </DIV><DIV> It could be that because I was in and out of the sub getting prepared for the test that the CO2 climbed a bit. But also I had this monitor running in my kitchen for a couple of days and I was amazed with the variation. For instance if I blew into it the readings would jump temporarily, I opened a loaf of bread next to it and the readings rose as well. </DIV><DIV> </DIV><DIV>Cliff, The readings tended to jump around probably because of air flow, like when I would stand up to look out of the top viewports and then sit down again I noticed they would jump up. I also ran a circulating blower fan every so often to try and mix the air. Yes I would have liked to have done a longer test and I do need to know how long until the 5000 ppm point with no O2 . The cabin pressure gauge did not budge, and I'm suspecting that I may have not had a tight seal on the hatch. I did however have my friend strap the hatch down from the outside for the very reason that I was worried about the seal. My hatch dogs will hold it snug but they are not a real positive crank down type seal, this is partly by design for an over pressure situation. My thought is that if I do have an overpressure situation then the hatch would burp out the excess pressure but sill remain closed and snug with the hatch dogs. I've done a vacuum test so I know it seals. I was thinking I would have a more positive seal using a crank down strap from the inside, but then if I had to be rescued that would have presented a problem. I think I may try to secure the hatch in that way and then bleed I a little air from a scuba tank to see if I can get the cabin pressure to go up by a half psi just so I can determine if my hatch is sealing or not. The volume inside my sub is around 95 cu ft so maybe it takes a lot to show any increase of psi. I'm using a analog flow meter to bleed in O2, the moving ball type.</DIV><DIV> </DIV><DIV>Brian</DIV><DIV> </DIV><DIV> </DIV><DIV> <BR><BR>--- personal_submersibles@psubs.org wrote:<BR><BR>From: "Sean T. Stevenson via Personal_Submersibles" <personal_submersibles@psubs.org><BR>To: personal_submersibles@psubs.org<BR>Subject: Re: [PSUBS-MAILIST] life support test<BR>Date: Mon, 19 Mar 2018 10:40:07 -0400<BR><BR>I am wondering about the apparent offset in the CO2 reading. You indicate a reading of 1225 ppm at hatch close. Assuming that this was the initial pretest reading before commencing any CO2 production in the closed environment, shouldn't that be closer to the 400 ppm typical of atmospheric air?<BR><BR>Sean<BR><BR><BR><BR>-------- Original Message --------<BR>On Mar 19, 2018, 08:30, Cliff Redus via Personal_Submersibles < personal_submersibles@psubs.org> wrote:</DIV><BLOCKQUOTE><BR><DIV dir="ltr"><DIV>Looks like progress on qualifying your life support system. A couple of observations. Your scrubber looks like it is controlling the CO2 level nicely. Humidity build looks normal. If you would have stayed in the boat longer, it would eventually plateau. The only thing that looks a little weak to me is the O2 concentration. It looks like your O2 makeup rate was a bit high, i.e., you are making up more O2 than you are consuming. If you looked at your results on a linear basis, the O2 would have reach the maximum acceptable ABS O2 concentration of 23% at 3.75 hours. Well short of the ABS 72 hour target. Not sure how you are controlling O2 makeup. The next thing I would do is do a longer test say 8-9 hours or how ever long it takes for your initial fill of CO2 absorbent to become saturated. The next test I would suggest is how long does it take for CO2 to build to 5000 ppm when O2 if off. Would also suggest you measure and report cabin pressure as this would tell you if you have a gas leak into the cabin. Also I would log the data more frequently say every 10 minutes to improve data analysis. You have nothing better to do while sitting in the boat. Also you might want to consider repeating the test with a low weight pilot to see how the system handle variation in CO2 generation and O2 consumption rates.</DIV><DIV><BR></DIV><DIV><BR></DIV><DIV>Keep up the good work.</DIV><DIV><BR></DIV><DIV>Cliff</DIV><DIV><BR></DIV></DIV><DIV><BR><DIV>On Sun, Mar 18, 2018 at 9:45 PM, Brian Cox via Personal_Submersibles <SPAN dir="ltr"><<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>></SPAN> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV style="font-family: Arial,sans-serif; font-size: 10pt;"><DIV>Hi All,</DIV><DIV> I did a life support test today ! Basically I threw a small party with a couple of friends and my wife. I was sealed in the sub for a total of about 2 1/2 hours .</DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> At the hatch closing time the readings were:</DIV><DIV> </DIV><DIV>O2 - 20.6 % CO2 1225 ppm Temp 79 F Humidity 50 %</DIV><DIV> </DIV><DIV> </DIV><DIV>In one hour the readings were:</DIV><DIV> </DIV><DIV>O2 - 21.4 % CO2 1365 ppm Temp79 humidity 63 %</DIV><DIV> </DIV><DIV> </DIV><DIV>At hour 2 readings were:</DIV><DIV> </DIV><DIV>O2 - 22.2 % CO2 1750 ppm Temp 77 F humidity 70 %</DIV><DIV> </DIV><DIV> </DIV><DIV>After 2 1/2 hours readings were :</DIV><DIV> </DIV><DIV>O2 - 22.2 % CO2 1785 ppm Temp 76 humidity 70 % </DIV><DIV> </DIV><DIV> </DIV><DIV>Brian</DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> </DIV><DIV> <BR><BR>--- <A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A> wrote:<BR><BR>From: Stephen Fordyce via Personal_Submersibles <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>><BR>To: Personal Submersibles General Discussion <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>><BR>Subject: Re: [PSUBS-MAILIST] life support test<BR>Date: Mon, 19 Mar 2018 10:59:31 +1100<BR><BR></DIV><DIV dir="auto">Hi Alan,<DIV dir="auto">Agreed the martini test probably is easier although I think that model is going to deviate the further you go.</DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">I had a friend (very experienced deep air diver) who was pushed to 60m/180ft by a current and he literally didn't have the mental faculty to save himself (he was fortunately holding a rope which I pulled up). </DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">If you're even still conscious breathing air at 100m/300ft you're doing pretty well. High oxygen seizures start to become a real risk beyond 70m on air, quite apart from how debilitating the narcosis will be.</DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">Cheers,</DIV><DIV dir="auto">Steve</DIV></DIV><DIV><BR><DIV>On 19 Mar 2018 10:23 am, "Alan via Personal_Submersibles" <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV dir="auto"><DIV>Steve,</DIV><DIV>you are advocating a nitrogen narcosis experience as a training for escape.</DIV><DIV>Nitrogen narcosis is known as the Martini effect & is equivalent to drinking</DIV><DIV>1 martini on an empty stomach for every 10 metres you descend.</DIV><DIV>I think a standard Martini is 3 oz, (some of the alcoholics in the group might</DIV><DIV>confirm this). It would be much easier to see how many Martini's you could</DIV><DIV>drink & still get out of your sub, than try & do a real simulation with nitrogen.</DIV><DIV>For those with K250s that's about 5 Martini's & K350's 8 at maximum depth.</DIV><DIV>I am shooting for 500ft so that's 12. (36oz)</DIV><DIV>How deep is Scott going?</DIV><DIV>Cheers Alan<BR><BR><DIV>Sent from my iPad</DIV></DIV><DIV><BR>On 19/03/2018, at 11:02 AM, Stephen Fordyce via Personal_Submersibles <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>> wrote:<BR><BR></DIV><BLOCKQUOTE><DIV><DIV dir="auto">Hi Brian and all,<DIV dir="auto">I'm just going through commissioning a new/modified rebreather which is a bit relevant to this. I believe (sort of at odds with conventional training manuals) that it's valuable to experience the physiological signs and symptoms of the various gases at incorrect levels. Your other systems should of course protect you and be highly conservative, but you never know.</DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">To that end, after a recent long dive I continued to breather the scrubber at home on the couch (for several hours) until the high CO2 effects were noticeable. I've also had a controlled low oxygen experience that I consider valuable. Both worth doing, maybe even regularly - I'd like to do high oxygen one but that's been a bit tricky so far.</DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">If anyone has plans to be exiting a partially flooded sub at depths below 30m/100ft then a nitrogen narcosis experience would be extremely valuable. Especially with quick compression, your mental faculties deteriorate rapidly. Even at that depth, and it gets worse as you go deeper. I don't dive below 50m on air because I barely know what I'm doing.</DIV><DIV dir="auto"><BR></DIV><DIV dir="auto">Cheers,</DIV><DIV dir="auto">Steve Fordyce</DIV></DIV><DIV><BR><DIV>On 18 Mar 2018 2:04 pm, "Cliff Redus via Personal_Submersibles" <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV dir="ltr">See <FONT face="Times New Roman" size="6"><FONT face="Times New Roman" size="6"></FONT></FONT><P align="LEFT"><FONT face="Times New Roman" size="6"><FONT face="Times New Roman" size="6"><B>DESIGN GUIDELINES </B></FONT></FONT><FONT face="Times New Roman" size="6"><FONT face="Times New Roman" size="6">FOR</FONT></FONT></P></DIV><FONT face="Times New Roman" size="6"><FONT face="Times New Roman" size="6">
<P align="LEFT">CARBON DIOXIDE SCRUBBERS
</P></FONT></FONT><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5"><P align="LEFT">I
</P></FONT></FONT><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5"></FONT></FONT><P align="LEFT"><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">MAY </FONT></FONT><B><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">1983</FONT></FONT></B><B><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">
</FONT></FONT></B><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5"></FONT></FONT></P><P align="LEFT"><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">REVISED </FONT></FONT><B><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">JULY 1985</FONT></FONT></B><B><FONT face="Times New Roman" size="5"><FONT face="Times New Roman" size="5">
</FONT></FONT></B><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3"></FONT></FONT></P><P align="LEFT"><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3">Prepared by
</FONT></FONT><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3">M. L. NUCKOLS, A. PURER, G. A. DEASON</FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3"><BR></FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3">for the philological affects of high CO2 level but if you abort the test if you ever exceed 5000 ppm, you should be safe. In addition to the CO2 issues, you should also familrrize yourself with both <STRONG><FONT color="#6a6a6a">Hypoxia</FONT></STRONG> which describes levels lower than Normoxia, or percentages lower than 21% and <EM><STRONG><FONT color="#6a6a6a">hyperoxic</FONT></STRONG></EM> breathing gas when levels rise above 22% of oxygen. Hypoxia would come from running out of makeup O2 or leaving the O2 supply valve closed by accident and hyperoic state would most likely be caused by a high pressure leak of O2 into the cabin caused by a loose fitting. I would recommend you abort the test if O2 concentration falls outside the acceptable range as defined by ABS.</FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3"><BR></FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3">When you go back and analyze the test, it is helpful to have data logged cabin atmosphere parameters including, CO2 and O2 concentrations, cabin pressure and temperature and relative humidity.</FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3"><BR></FONT></FONT></DIV><DIV><FONT face="Times New Roman" size="3"><FONT face="Times New Roman" size="3">Cliff</FONT></FONT></DIV><DIV></DIV><DIV><BR><DIV>On Sat, Mar 17, 2018 at 5:37 PM, Brian Cox via Personal_Submersibles <SPAN dir="ltr"><<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>></SPAN> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV style="font-family: Arial,sans-serif; font-size: 10pt;"><DIV>Hi All,</DIV><DIV> Thinking about testing my life support. Will obviously have some people outside the sub watching me, and talking via radio. But I was wondering if there would be a point at which I should abort the test when the CO2 gets to a certain point . If it levels off and stays at a constant but is some what elevated would it be ok to monitor that situation ? Like say it levels off at 2000 ppm and assuming my oxygen is at a constant 20.8 % ? </DIV><SPAN><FONT color="#888888"><DIV> </DIV><DIV>Brian</DIV><DIV> </DIV><DIV> </DIV></FONT></SPAN></DIV>
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