<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div><span></span></div><div>Rick,</div><div id="yui_3_16_0_ym19_1_1487353419653_3848">An altimeter is still a good idea, I think anyways. First it will let you know if you have an over or under pressure and it will never let you down, like electronics can. The altimeter will verify what your instruments are telling you. If your altitude is going up then your pressure is dropping witch means you add O2 . If your altitude is dropping then your pressure is increasing witch means you are either adding to much O2 or your scrubber is not keeping up. Relying on just an altimeter in not good either because you can get pressure changes from temperature changes. The sub will drop in temperature in cold water when you sink, that will cause a drop in pressure witch has nothing to do with environmental control. </div><div id="yui_3_16_0_ym19_1_1487353419653_3847">Hank</div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> On Friday, February 17, 2017 10:37 AM, Rick Patton via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv8703843996"><div><div dir="ltr">If I have a good 02 and C02 sensor, should I still have an altimeter and how would I base the altimeter reading for adding 02? <div><br clear="none"></div><div>Rick</div></div><div class="yiv8703843996gmail_extra"><br clear="none"><div class="yiv8703843996gmail_quote">On Fri, Feb 17, 2017 at 5:43 AM, Sean T. Stevenson via Personal_Submersibles <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none"><blockquote class="yiv8703843996gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="yiv8703843996yqt7319096581" id="yiv8703843996yqt89406"><div>
<div class="yiv8703843996m_-8217462566956995560moz-cite-prefix">I don't recall seeing insulation in the
DW2000 either. Perhaps Phil will chime in on this? It is
possible that being so compact, the surface area of the DW hull is
small enough that the contained heat loads can keep up to the
moisture production. Also, those are certified through GL, and as
such may have different requirements than ABS's 30% - 70% RH. Can
anyone speak to the GL rules on this? I can't see avoiding a 100
% RH environment, and the consequent condensation, when submerged
in 5°C water without either insulating or employing dessicants to
remove the moisture. Immediately next to the hull, it will always
be colder, so you may get condensation on the hull despite being
within humidity limits on the cabin air on average. I was
thinking that a cylindrical pressure hull would be relatively
simple to insulate though, with something like AP Armaflex sheet
material. You wouldn't even necessarily need to apply at 100%
coverage, but rather just enough to reduce the heat loss to meet
the 70% RH limit at whatever your cabin temperature is. (14°C -
30°C are the recommended temperature limits, but that's not
actually a rule under ABS UWVS). Insulating just the large
cylindrical surfaces between frames might be sufficient. In my
own design, insulation is a necessity - otherwise I won't be able
to keep my coffee hot.<br clear="none">
<br clear="none">
Sean<br clear="none">
<br clear="none">
<br clear="none">
On 2017-02-15 17:41, hank pronk via Personal_Submersibles wrote:<br clear="none">
</div>
<blockquote type="cite">
<div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px;">
<div><span>Sean,</span></div>
<div dir="ltr" id="yiv8703843996m_-8217462566956995560yui_3_16_0_ym19_1_1487205274876_5828"><span>I
can not remember the temperature over the length of a
typical dive. I would estimate 10C after 1\2 hr at 100
feet. When I dive Kootenay lake it is probably 5C </span></div>
<div dir="ltr" id="yiv8703843996m_-8217462566956995560yui_3_16_0_ym19_1_1487205274876_5828"><span>I
wonder how DW's manage, they dive all over the world and I
am sure in the winter.</span></div>
<div dir="ltr" id="yiv8703843996m_-8217462566956995560yui_3_16_0_ym19_1_1487205274876_5828"><span>Hank</span><br clear="none">
</div>
</div>
</blockquote>
<br clear="none">
</div></div>
<br clear="none">______________________________ _________________<br clear="none">
Personal_Submersibles mailing list<br clear="none">
<a rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" target="_blank" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs. org</a><br clear="none">
<a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/ listinfo.cgi/personal_ submersibles</a><br clear="none">
<br clear="none"></blockquote></div><br clear="none"></div></div></div><br><div class="yqt7319096581" id="yqt19145">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>