I watched almost all of your educational videos here, but now is the time when I realized that you are an excellent teacher too! We love you, Jonathan!
Hello Jonathan, okay I understand you’re not an Instructor but you’re a perfect Communicator and it’s a great pleasure to follow your explanation of how things work. I also like the submarine decoration on your Set. I have been a recreational diver for some years and I am very interested how dive technology evolves. Thank you for your great work. Greetings from Vienna/ Austria
Great video. In general, it would be nice to see a video about a standard training progression from, say, OW certs to rebreather (and maybe cavern and cave too). it’s sort of overwhelming figuring out what the right training progression is. obviously depends on what the diver wants to do in the future, but maybe learning about your course progression would be helpful!
Jonathan we appreciate your expert skill in conveying technical concepts in a fun and enjoyable format. Keep on doing what you do as each of your talks are engaging and founded on scientific principals. 🤙Cheers, #SeattleRingHunter
As a diver about to do a test dive on a rebreather for the first time ever I like knowing there’s multiple sensors keeping me alive welp here I go down an expensive road 😂❤️
i really enjoy your videos. id dive with you guys for sure. i will also say that youve really brought me back to KISS verses an eccr that i was considering. im starting to really feel the simplicity of the design is a better path for most-- rely on your own education and capabilities rather than a more complicated eccr to do everything for you.
Great video thanks, makes sense to test the sensors to see if they are current limited but we are told to splash in with a low set point say 0.7 typically, whereas this test suggests we jump in at 1.0. Believe there is some ambiguity here from the agencies? Thoughts?
Hey🎉😮🎉 now i know why i can sand off a thermocouple attached to a hot water heater gas valve and I can relight the water heater gas valve. . Its a discimilar metal galvanic rod that generates curent that opens the gas controle valve when the pilot heats The rod and causes the current to flow.😊
Really good video, thank you very much for that! If rebreather weren´t that expensive, I would own one already :-D But I do have a question: Did you get into the topic of the "new" solid state oxygen sensors? Do you have any experience with them?
I have never tried one, but Richard Pyle, who has more time on rebreathers than literally anyone in the world, says that they are amazing and as soon as the price comes down, nobody will look back.
you shouldn't need to dive to test it, just calibrate at the surface with an 02 purge then purge with air it should read 0.2, I suppose you could purge with nitrox 32 or whatever it should read .32, am I wrong? Also a simple box could be made that you can put your sensors in that holds pressure to test them at greater than 1bar.
The way I was taught is to do both. Your "pre-breathe" at the surface is a double check. It checks that the sensors are working and it also is a check that your diluent is what you think it is. (There have been deaths attributed to people assuming the wrong diluent for the depth they were going.). Once you get to 20 feet, a second check assures that the sensors are working at full voltage.
why dont you do three or four different gas mixes and use those points to calibrate? Then you automatically can check weather your sensor ist too old. I mean if you get your oxigen from a blending station you can get a bit of nitrox with xy O2 as well. With modern computers you should be able to calibrate for several O2 levels at 1 atmoosphere. Am I wrong?
@@BlueWorldplus thinking about it, it seems reasonable. Otherwise there would be an additional possible failure point if one doesn't exactly know the oxygen in the gas mix. I.e. if its 32,3 instead of 34%.
A diluent flush would allow you to visually confirm on the HUD or handset the low end of the scale while at the surface, and during the dive you could calculate it for a given depth. If you were using air or 21/35 for diluent at 20’ depth after a flush you should show PO2 of 0.34. The diluent flush procedure is used at any depth to help troubleshoot the O2 sensors. Some units will also have an independent 4th sensor so you can confirm between the hand set and HUD.
Great explanation. But still: Nowadays there are highly reliable solid state oxygen sensors that have virtually unlimited lifetime - rated for ten years even in safety critical gas monitoring devices. I cannot understand why rebreather manufacturers don't use them. These electrochemical sensors are clearly less safe and much more expensive due to frequent changes.
The problem is that solid state oxygen sensors requiers change in construction of the head of rebreather, also as for now poseidon is testing this but this is propioritary technology of this manufacturer so other producents would have basicly to buy this technology from them or invest a lot of money in developing similar system of their own
@@BlueWorldplus GUE published an article about the subject on their blog back in 2021, you can find it by googling "What Happened to Solid State Oxygen Sensors?". The essence was, that it is possible but still requires a lot of research and development to make them work reliably and accurate in the environmental conditions inside a rebreather. That's how I came to the conclusion that we still don't see solid state sensors in most rebreathers because manufacturers don't like to spend money on research and development.
The main issue is that those sensors requier external power to run (not like galvanic sensors that are basicly batteries) so you have to change build of whole electronics in head, as far as the problems with those sensors - I havent`t found any informations about problems only that they work great for long period of time (some were tested for much longer than 5 years without any problems) The second may be the cost of investment in those sensors (they are quite pricy but this is neglegble comparing to switching normal sensors for couple of years)
@@robit024 I would have expected they'd digitize sensor readouts in the head electronics in order to transfer them via CAN bus or some similarly reliable digital protocol to the controllers. Your description implies that they run the analog sensor voltage through the cable and even a plugged connection and then do the AD conversion in the controllers. Is that really true? Doesn't sound like a smart idea to me...
once i burnrd up all three sensors. i flooded my loop and took a hit at 40 feet. my mouth and throat were swollen and i dumped my sport kiss in thecshower.
@@BlueWorldplus Almost every diver death I read about is someone using a rebreather that malfunctioned or was incorrectly assembled; equipment is rarely the cause of open circuit scuba fatalities.
@@jonnieinbangkokyou will see OC divers enter the water without opening their cylinder valve, hooking up their LP inflator or drysuit hose. I’ve seen OC divers exceed their recreation contingent MOD to reach a depth on a dive. People do dumb things, and human factors and not following procedures will bite you no matter what equipment you use.
I watched almost all of your educational videos here, but now is the time when I realized that you are an excellent teacher too! We love you, Jonathan!
Thanks!
Hello Jonathan, okay I understand you’re not an Instructor but you’re a perfect Communicator and it’s a great pleasure to follow your explanation of how things work. I also like the submarine decoration on your Set. I have been a recreational diver for some years and I am very interested how dive technology evolves. Thank you for your great work. Greetings from Vienna/ Austria
I appreciate that! Thanks!
I have no plan to do CCR but you explain this so well that I am properly down the rabbit hole! Maybe I will look into CCR after all…
Excellent presentation on Oxygen sensors. It cleared up several questions I had on those little guys. Keep those videos coming. 🙂
Thanks, will do!
Next Scuba 101 will be about trimix
Jonathan, thank you for the good explanation man!
This is a video every diver should watch!! Very good !!
Thanks!
Great video. In general, it would be nice to see a video about a standard training progression from, say, OW certs to rebreather (and maybe cavern and cave too). it’s sort of overwhelming figuring out what the right training progression is. obviously depends on what the diver wants to do in the future, but maybe learning about your course progression would be helpful!
Fenomenal educational content there, but I would disagree with the title, it's not "all" about CCR oxygen sensors - only galvanic ones. 😉
There is a lot of promise in the solid state O2 sensors, but they are far from mainstream yet, not to mention they are over $1K each.
Science of O2 sensors, way cool and thanks for the presntation
Very informative video about sensors. Good work, thanks.
Happy diving
A very good episode and excellent explanation! Thank you.
Glad you enjoyed it!
Always wondered, how those little babies work. Thank you!❤
Jonathan we appreciate your expert skill in conveying technical concepts in a fun and enjoyable format. Keep on doing what you do as each of your talks are engaging and founded on scientific principals. 🤙Cheers, #SeattleRingHunter
As a diver about to do a test dive on a rebreather for the first time ever I like knowing there’s multiple sensors keeping me alive welp here I go down an expensive road 😂❤️
Wonderful. Very educative
very well explained. thanx so much
i really enjoy your videos. id dive with you guys for sure. i will also say that youve really brought me back to KISS verses an eccr that i was considering. im starting to really feel the simplicity of the design is a better path for most-- rely on your own education and capabilities rather than a more complicated eccr to do everything for you.
100%. When you dive a KISS you are completely in control and it's so simple.
Great video. Thanks
Its simply awesome what you do, so thank you very much for your efforts !!
Great video thanks, makes sense to test the sensors to see if they are current limited but we are told to splash in with a low set point say 0.7 typically, whereas this test suggests we jump in at 1.0. Believe there is some ambiguity here from the agencies? Thoughts?
I'm not an instructor. LOL. I'm just saying how I do it.
Please explain the different types of connectors for each sensor. Ex: Molex, SMB, Coax....
Hey🎉😮🎉 now i know why i can sand off a thermocouple attached to a hot water heater gas valve and I can relight the water heater gas valve. . Its a discimilar metal galvanic rod that generates curent that opens the gas controle valve when the pilot heats
The rod and causes the current to flow.😊
Great episode! Thank you!
Glad you enjoyed it!
Great! Now do one on Solid State sensors!
I don't know that much about them, but from what I have heard, they are going to be the better way to go once the price comes down a little.
Any chance you have any knowledge on the solid state cells use on the Poseidon MKVII unit?
Here is a good article about them:
gue.com/blog/what-ever-happened-to-solid-state-sensors/
Top video squire
Really good video, thank you very much for that! If rebreather weren´t that expensive, I would own one already :-D But I do have a question: Did you get into the topic of the "new" solid state oxygen sensors? Do you have any experience with them?
great. i will usr my old Scubapro analog depth guage to tedt my O2 sensor at 20 feet.
Well, that's one way to get them through TSA....
video STREPITOSO !!!!!🙂
Can you comment on gifting used sensors to your open circuit buddies to use in their nitrox analyser?
As a general rule, if a sensor is weak enough that you can't use it in a rebreather, you shouldn't use it for an analyzer.
now i really wonder why they are so expensive if they are "oxygen" batteries.. my ones cost around 160$ plus shipping
Hey there!
When does the video about solid state oxygen sensors come out? 😇
gue.com/blog/what-ever-happened-to-solid-state-sensors/
how do you like thr new solid state sensor?
I have never tried one, but Richard Pyle, who has more time on rebreathers than literally anyone in the world, says that they are amazing and as soon as the price comes down, nobody will look back.
Can their shelf life be prolonged drastically by storing them in a sealed box with 0% O2 ?
That's what I do. I put them in a sealed bag with Argon.
you shouldn't need to dive to test it, just calibrate at the surface with an 02 purge then purge with air it should read 0.2, I suppose you could purge with nitrox 32 or whatever it should read .32, am I wrong? Also a simple box could be made that you can put your sensors in that holds pressure to test them at greater than 1bar.
The way I was taught is to do both. Your "pre-breathe" at the surface is a double check. It checks that the sensors are working and it also is a check that your diluent is what you think it is. (There have been deaths attributed to people assuming the wrong diluent for the depth they were going.). Once you get to 20 feet, a second check assures that the sensors are working at full voltage.
At PO2=0 voltage is always 0, right? At this point (0, 0) all lines should cross.
Correct, the device can't function without oxygen.
What happens if the sensors are immersed? Shorts?
If they get wet, they do not work. That is one of the challenges of rebreather design--making sure that the O2 sensors stay dry.
Funny thing to say as rebreathers have been around since ww2 without oxygen sensors.
Earlier than that actually.
why dont you do three or four different gas mixes and use those points to calibrate? Then you automatically can check weather your sensor ist too old. I mean if you get your oxigen from a blending station you can get a bit of nitrox with xy O2 as well. With modern computers you should be able to calibrate for several O2 levels at 1 atmoosphere. Am I wrong?
Computers are set to calibrate at pure O2 only.
@@BlueWorldplus thinking about it, it seems reasonable. Otherwise there would be an additional possible failure point if one doesn't exactly know the oxygen in the gas mix. I.e. if its 32,3 instead of 34%.
A diluent flush would allow you to visually confirm on the HUD or handset the low end of the scale while at the surface, and during the dive you could calculate it for a given depth. If you were using air or 21/35 for diluent at 20’ depth after a flush you should show PO2 of 0.34. The diluent flush procedure is used at any depth to help troubleshoot the O2 sensors. Some units will also have an independent 4th sensor so you can confirm between the hand set and HUD.
Great explanation.
But still:
Nowadays there are highly reliable solid state oxygen sensors that have virtually unlimited lifetime - rated for ten years even in safety critical gas monitoring devices.
I cannot understand why rebreather manufacturers don't use them. These electrochemical sensors are clearly less safe and much more expensive due to frequent changes.
The problem is that solid state oxygen sensors requiers change in construction of the head of rebreather, also as for now poseidon is testing this but this is propioritary technology of this manufacturer so other producents would have basicly to buy this technology from them or invest a lot of money in developing similar system of their own
There is no question that the solid state ones are the future. I don't know much about them, but how do they handle extremely humid environments?
@@BlueWorldplus GUE published an article about the subject on their blog back in 2021, you can find it by googling "What Happened to Solid State Oxygen Sensors?". The essence was, that it is possible but still requires a lot of research and development to make them work reliably and accurate in the environmental conditions inside a rebreather.
That's how I came to the conclusion that we still don't see solid state sensors in most rebreathers because manufacturers don't like to spend money on research and development.
The main issue is that those sensors requier external power to run (not like galvanic sensors that are basicly batteries) so you have to change build of whole electronics in head, as far as the problems with those sensors - I havent`t found any informations about problems only that they work great for long period of time (some were tested for much longer than 5 years without any problems) The second may be the cost of investment in those sensors (they are quite pricy but this is neglegble comparing to switching normal sensors for couple of years)
@@robit024 I would have expected they'd digitize sensor readouts in the head electronics in order to transfer them via CAN bus or some similarly reliable digital protocol to the controllers. Your description implies that they run the analog sensor voltage through the cable and even a plugged connection and then do the AD conversion in the controllers.
Is that really true? Doesn't sound like a smart idea to me...
once i burnrd up all three sensors.
i flooded my loop and took a hit at 40 feet. my mouth and throat were swollen and i dumped my sport kiss in thecshower.
Yikes!
So much easier diving open circuit...and you don't die.
People still manage to die.
@@BlueWorldplus Almost every diver death I read about is someone using a rebreather that malfunctioned or was incorrectly assembled; equipment is rarely the cause of open circuit scuba fatalities.
@@jonnieinbangkokyou will see OC divers enter the water without opening their cylinder valve, hooking up their LP inflator or drysuit hose. I’ve seen OC divers exceed their recreation contingent MOD to reach a depth on a dive. People do dumb things, and human factors and not following procedures will bite you no matter what equipment you use.
@@Chogogo717 Yes, but OC gear isn't actively trying to kill you 😆