<html><head></head><body>You are correct, the naive formula, assuming ideal gases, does indeed give different results than what Subsurface shows you.<br>Subsurface takes gas compressibility into account which leads to slightly different and generally lower consumption numbers.<br><br>Details have been explained very nicely here in a post of one of our developers <a href="https://thetheoreticaldiver.org/wordpress/index.php/2017/11/02/when-real-gas-corrections-matter/">https://thetheoreticaldiver.org/wordpress/index.php/2017/11/02/when-real-gas-corrections-matter/</a><br><br>You can also find many threads about this topic in the archives...<br><br>/D<br><br><div class="gmail_quote">On December 31, 2021 4:40:08 AM HST, "Oliver@Koschorreck via subsurface" <subsurface@subsurface-divelog.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre dir="auto" class="k9mail">Hi<br>unfortunately the air consumption calculation seems to be incorrect !<br>Bottle volume, start air pressure minus end air pressure, divided by <br>time Divided by avarage depth = AMV liters / min.<br>Unfortunately, the bill is always too little.<br><br> Greetings and thanks Oliver Koschorreck<br><br><br><br>Hallo<br>leider scheint die Luftverbrauchs Rechnung fehlerhaft zu sein !<br>Flaschenvolumen, Start Luftdruck minus Ende Luftdruck, Dividiert durch <br>Zeit Dividiert durch avarage Tiefe = AMV Liter /min.<br>Leider ist die Rechnung immer zu wenig.<br><br> Grüße und Danke Oliver Koschorreck<br><br><br><div class="k9mail-signature">-- <br>Oliver Koschorreck<br>Richard-Wagner Str. 69<br>69259 Wilhelmsfeld<hr>subsurface mailing list<br>subsurface@subsurface-divelog.org<br><a href="http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface">http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface</a><br></div></pre></blockquote></div><div style='white-space: pre-wrap'><div class='k9mail-signature'>-- <br>from my phone</div></div></body></html>