<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>That's worth looking for Hank. </div><div>Could be expensive with the high pressure & salt water we are dealing with.</div><div>I saw this wireless system that has a minimum 10 M range, but only indicates</div><div>low tank pressure.</div><div><a href="http://desertstar.com/product/air-pressure-alert-system-apa/">http://desertstar.com/product/air-pressure-alert-system-apa/</a></div><div>Alan</div><div><br><br>Sent from my iPad</div><div><br>On 3/11/2016, at 1:15 am, hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_ym19_1_1478088642436_9199"><span>Alan,</span></div><div id="yui_3_16_0_ym19_1_1478088642436_9199" dir="ltr"><span id="yui_3_16_0_ym19_1_1478088642436_9401">There is a hydraulic component on cranes etc the allows oil to flow at a set rate, but if the flow increases dramatically the component becomes a shut off valve. This is to protect people and equipment in case a hose or seal blows out. maybe there is aa air </span>equivalent?</div><div id="yui_3_16_0_ym19_1_1478088642436_9199" dir="ltr">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 Wednesday, November 2, 2016 3:43 AM, Alan James via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv8957119398"><div><div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4220"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4219">I just experimented with the flow from the high pressure port</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4182"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4218">on my 1st stage regulator. That's the one your pressure gauge runs off.</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4181"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4217">Even though the hole is literally a pin prick, I was getting at least</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4162"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4161">2 liters a second flow out of it. </span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4160"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4159">I am building a similar sized sub to Cliff's R300 & a leak like that,</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4164"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4163">apart from increasing the pressure massively, would be hazardous</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4292"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4291">if it was O2. In 4 minutes I could have 70% O2 based on an air</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4294"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4300">volume in the sub of 250 liters.</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4317"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4334">I think I'll go for a pressure gauge outside my view port or try potting</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4346"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4345">a digital pressure gauge & just send the wires through a penetrator.</span></div><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4353"><span id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4360">Alan</span></div><div class="yiv8957119398qtdSeparateBR" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4078"><br clear="none"><br clear="none"></div><div class="yiv8957119398yahoo_quoted" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4158" style="display:block;"> <div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4157" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4156" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4215"> <font id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4214" face="Arial" size="2"> </font><div class="yiv8957119398yqt3942443728" id="yiv8957119398yqtfd67376"><hr id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4216" size="1"> <b><span style="font-weight:bold;">From:</span></b> Alan via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> <b><span style="font-weight:bold;">To:</span></b> Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> <br clear="none"> <b><span style="font-weight:bold;">Sent:</span></b> Wednesday, November 2, 2016 12:41 AM<br clear="none"> <b><span style="font-weight:bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Electronic contents gauge<br clear="none"> </div></div><div class="yiv8957119398yqt3942443728" id="yiv8957119398yqtfd31492"> <div class="yiv8957119398y_msg_container" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4155"><br clear="none"><div id="yiv8957119398"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4212"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4213">Thanks for the advice Steve.</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4211">I haven't looked in to the electronic oxygen add system too deeply.</div><div>Bound to have some questions later on.</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4375">Cheers Alan</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4376"><br clear="none">Sent from my iPad</div><div class="yiv8957119398yqt3305599012" id="yiv8957119398yqt51556"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4377"><br clear="none">On 1/11/2016, at 9:39 pm, Stephen Fordyce via Personal_Submersibles <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none"><br clear="none"></div><blockquote id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4381" type="cite"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4380"><div dir="ltr" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4379"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4378">Thanks Alan - I should probably point out that my Watchdogs are rather literally named - ie. they can sense something is wrong and do something simple about it, but are limited in how complex the reaction can be. It can only handle one O2 input, and the control is limited by controller settings - it's an off-the-shelf item and not fully programmable like a PLC. Good for an independent backup or alarm. As a primary system it could be made to work but would require a thoughtful setup.</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4382"><br clear="none"></div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4383">Eventually I do plan to make a rebreather controller (for the rebreather I'm designing) which would be perfect (many O2 cell inputs and a solenoid or two output), but that's a while away!</div><div><br clear="none"></div><div>A key thing to consider in automatic oxygen adding is placement of sensors, natural mixing of the air and sufficient time delay in the control system to get meaningful feedback before the next oxygen injection (Ie. rebreather controllers squirt a little bit of oxygen in, wait a few seconds for it to mix, and then measure, and squirt in more accordingly).</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4384"><br clear="none"></div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4385">Cheers,</div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4386">Steve</div><div><br clear="none"></div><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4387">PS: I also have some M12 plated brass Blue Globe cable glands if you find yourself short a couple - very hard to get down here.</div><div><br clear="none"></div><div><br clear="none"></div></div><div class="yiv8957119398gmail_extra" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4393"><br clear="none"><div class="yiv8957119398gmail_quote" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4392">On Tue, Nov 1, 2016 at 2:19 PM, Alan James 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="yiv8957119398gmail_quote" id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4391" 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 id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4390"><div id="yiv8957119398yui_3_16_0_ym19_1_1478077967724_4389" style="color:rgb(0, 0, 0);font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;background-color:rgb(255, 255, 255);"><div id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3134"><br clear="none">Steve,</div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3183">sending this again as I didn't receive it...</div><div id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3186"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3187">Steve,</span></div><div id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3188"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3189">I am wanting to build an O2 system like James Cameron had.</span></div><div id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3190"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3191">An O2 valve that flows continuously with a top up from a solenoid</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3192"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3193">valve which triggered by a plc that is receiving signals from 3 x O2 sensors. </span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3194"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3195">Mainly because I want to keep everything as small as possible.</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3196"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3197"> With your O2 unit it looks like you could have it doing similar;</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3198"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3199">turn on a solenoid to top up the O2 beyond what is flowing in from</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3200"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3201">a pre-set valve. A bellows add system that replaces the bellows with</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3202"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3203">your "Oxygen Watchdog"</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3204"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3205">Know what you mean about UK freight charges, have cancelled items</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3206"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3207">because of ridiculous freight charges. Thanks for the offer of buying</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3208"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3209">through your firm.</span></div><div dir="ltr" id="yiv8957119398m_-1904202565053152574yiv7750647722yui_3_16_0_ym19_1_1477958744792_5053"><span id="yiv8957119398m_-1904202565053152574yui_3_16_0_ym19_1_1477970226444_3211">Cheers Alan</span></div></div></div><br clear="none">______________________________ _________________<br clear="none">
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