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<div dir="ltr" data-setdir="false" style="">For a Psub Life Support standard, I think you should stick with ABS rules as much as possible. For sure being able to measure, control and set alarm states for CO2 and O2 at the level you notes are critical. Other parameters like cabin temperature and relative humidity (RH) I think are important to measure for safety reason but not control. If you measure RH and cabin temperature them you can calculate the the Heat Index in the boat from <a href="https://byjus.com/heat-index-formula/" rel="nofollow" target="_blank" style="font-family: times new roman, new york, times, serif; font-size: 16px;" class="enhancr_card_8615154467">Heat Index Formula Celsius - Definition, Formula And Solved Examples (byjus.com)</a> which is nice to know given we dive in hot climates and normally don't have AC in the boats. I personally think +/1 1 psi is a bit tight and +/- 2 psi is adequate. As Sean notes, ABS rules call out for the control of humidly and temperature. I think this is a bit to constraining for PSub world and I don't know of any PSubs.org boats that have AC control.</div><div dir="ltr" data-setdir="false" style=""><br></div><div dir="ltr" data-setdir="false" style="">Cliff</div><div><br></div><div id="ydp55a25710enhancr_card_8615154467" class="ydp55a25710yahoo-link-enhancr-card ydp55a25710ymail-preserve-class ydp55a25710ymail-preserve-style" style="max-width:400px;font-family:YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif" data-url="https://byjus.com/heat-index-formula/" data-type="YENHANCER" data-size="MEDIUM" contenteditable="false"><a href="https://byjus.com/heat-index-formula/" style="text-decoration:none !important;color:#000 !important" class="ydp55a25710yahoo-enhancr-cardlink" rel="nofollow" target="_blank"><table border="0" class="ydp55a25710card-wrapper ydp55a25710yahoo-ignore-table" cellpadding="0" cellspacing="0" style="max-width:400px"><tbody><tr><td width="400"><table border="0" class="ydp55a25710card ydp55a25710yahoo-ignore-table" cellpadding="0" cellspacing="0" width="100%" style="max-width:400px;border-width:1px;border-style:solid;border-color:rgb(224, 228, 233);border-radius:2px"><tbody><tr><td class="ydp55a25710card-primary-image-cell" background="https://s.yimg.com/lo/api/res/1.2/jHnAmZQmAIqTCRhn7_2clA--~A/Zmk9ZmlsbDt3PTQwMDtoPTIwMDthcHBpZD1pZXh0cmFjdA--/https://cdn1.byjus.com/images/fb-share-button-k10-k12.png.cf.jpg" bgcolor="#000000" valign="top" height="175" style="background-color: rgb(0, 0, 0); background-size: cover; position: relative; border-radius: 2px 2px 0px 0px; min-height: 175px;"><!--[if gte mso 9]><v:rect fill="true" stroke="false" style="width:396px;height:175px;position:absolute;top:0;left:0;"><v:fill type="frame" color="#000000" src="https://s.yimg.com/lo/api/res/1.2/jHnAmZQmAIqTCRhn7_2clA--~A/Zmk9ZmlsbDt3PTQwMDtoPTIwMDthcHBpZD1pZXh0cmFjdA--/https://cdn1.byjus.com/images/fb-share-button-k10-k12.png.cf.jpg"/></v:rect><![endif]--><table border="0" class="ydp55a25710card-overlay-container-table ydp55a25710yahoo-ignore-table" cellpadding="0" cellspacing="0" style="width:100%"><tbody><tr><td class="ydp55a25710card-overlay-cell" background="https://s.yimg.com/cv/ae/nq/storm/assets/enhancrV21/1/enhancr_gradient-400x175.png" bgcolor="transparent" valign="top" style="background-color: transparent; border-radius: 2px 2px 0px 0px; min-height: 175px;"><!--[if gte mso 9]><v:rect fill="true" stroke="false" style="width:396px;height:175px;position:absolute;top:-18px;left:0;"><v:fill type="pattern" color="#000000" src="https://s.yimg.com/cv/ae/nq/storm/assets/enhancrV21/1/enhancr_gradient-400x175.png"/><v:textbox inset="0,0,20px,0"><![endif]--><table border="0" class="ydp55a25710yahoo-ignore-table" height="175" style="width: 100%; min-height: 175px;"><tbody><tr><td class="ydp55a25710card-richInfo2" style="text-align:left;padding:15px 0 0 15px;vertical-align:top"></td><td class="ydp55a25710card-actions" style="text-align:right;padding:15px 15px 0 0;vertical-align:top"><div class="ydp55a25710card-share-container"></div></td></tr></tbody></table><!--[if gte mso 9]></v:textbox></v:rect><![endif]--></td></tr></tbody></table></td></tr><tr><td><table border="0" align="center" class="ydp55a25710card-info ydp55a25710yahoo-ignore-table" cellpadding="0" cellspacing="0" style="background:#fff;position:relative;z-index:2;width:100%;max-width:400px;border-radius:0 0 2px 2px;border-top:1px solid rgb(224, 228, 233)"><tbody><tr><td style="background-color:#ffffff;padding:16px 0 16px 12px;vertical-align:top;border-radius:0 0 0 2px"></td><td style="vertical-align:middle;padding:12px 24px 16px 12px;width:99%;font-family:YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif;border-radius:0 0 2px 0"><h2 class="ydp55a25710card-title" style="font-size: 14px; line-height: 19px; margin: 0px 0px 6px; font-family: YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif; color: rgb(38, 40, 42); max-width: 314px;">Heat Index Formula Celsius - Definition, Formula And Solved Examples</h2><p class="ydp55a25710card-description" style="font-size: 12px; line-height: 16px; margin: 0px; color: rgb(151, 155, 167);">The Heat Index (HI) is an equation combining air temperature and relative humidity to determine the equivalent t...</p></td></tr></tbody></table></td></tr></tbody></table></td></tr></tbody></table></a></div><div><br></div><div><br></div><div style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div>
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On Sunday, December 13, 2020, 11:43:40 AM CST, Jon Wallace via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
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<div><div id="ydp4ce13cd2yiv9820458856"><div><div class="ydp4ce13cd2yiv9820458856yahoo-style-wrap" style="font-family:times new roman, new york, times, serif;font-size:16px;"><div dir="ltr">I'm looking to start a discussion to create a PSUBS standard for max/min cabin operating conditions. I'm not convinced temp or humidity matter all that much overall and require an agreement. I would start with the following:</div><div dir="ltr"><br></div><div dir="ltr">O2: 19.0 to 23 percent</div><div dir="ltr">CO2: 0 to 5000 ppm</div><div dir="ltr">Pressure: +/- 1psi</div><div dir="ltr"><br></div><div dir="ltr">Comments?</div></div></div></div>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org" rel="nofollow" target="_blank">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="nofollow" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></div>
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