NOWDIVE TV, 3 Myths about your pressure gauge on your diving equipment

In this video we will bust 3 myths surrounding our trusted scuba submersible pressure gauge.

[@marcstrauven4697]

This is a very good explanation,very GOOD. When I started to dive in 1997 they told me 50 BARS is RESERVE , NELOS DIVE SCHOOL!!!! They changed to 100 BARS later. PLAN YOURE DIVE AND DIVE YOURE PLAN and calculate reserve specific for each dive is better. You are a very good instructor.

[@szveha]

For me the last part about air consumption is very interesting!!! Thanks!!

[@johnnyf4r]

Excellent, keep up the good work

[@Chogogo717]

They should really teach this in open water. I’m going through my training currently. Thanks for doing a better job than PADI.

[@oneworld3719]

You are amazing! you are teaching us to use our brain also while diving :) it's pretty useful as I have long time questions and searching for an answer about how much Air did I am using during this deep as I want to be able calculated up front. Thank you so much for this education, respect!!!!

[@licurgius]

This is soo valuable if you serious about diving. I’m glad you switched to English - what you are sharing is too valuable to stay confined to Danish speaking divers only. I bing watched your videos, even some danish, and it’s really great stuff - learned way more new and usefull things from it then from the divemaster program I just completed

[@maxtorque2277]

SPG's "explode" (they don't actually explode of course) because there internal volume gets slowly filled by the high pressure air from the cylinder, and when that reaches the burst pressure of the unit (assuming it hasn't got a blow out pressure relief plug) then the SPG "explodes". To simulate this you would need to carefully open an spg, and drill a tiny hole into the bowden tube to simulate the small crack that can appear due to the repeated flexing of that tube over time. That hole then allows the inside of the spg to pressurise, and given that this volume is typically around 20cc, at a typical burst pressure of 100 bar, that's 2 litres of air in their, just waiting to burst out and propel parts of the spg away at some significant speed. You can see the same effect if you cut into a HP hose that is pressurised, and the inital "POP" is considerable as the volume of the hose blows down, but the eventual leak rate is fairly small because of the small hole upstream in the 1st stage output fitting. Now, SPG "exploding" are rare, and modern ones with pressure blow out plugs really are even safer, but i see no reason not to sensible make sure the SPG and hose are away from you when you initally turn the cylinder on. It's not hard to do, it takes no longer to do, so why not? IME, it's more important to make sure you open the cylinder valve slowly to ensure the 1st stage has time to catch and hold the IP without any dynamic effects, ie large pressure spikes travelling down the "low pressure" (actually IP) hoses towards your second stages and BCD/drysuit inflators etc. These spikes can cause a hose to fail,which will then tend to whip and flail around and whilst not presenting that much energy in absoluet terms, getting hit in the face or eyes with the end of failing hose is probably going to ruin your day at the least!

[@divingmadd6219]

Great Video! Keep up the awesome English videos!

[@cmfamonteiro]

this is a very usefull and helping video. tank you

[@derekjhanna]

I've also seen a window pop off a slim SPG. It's fairly rare but does happen.

[@kozebamze]

Good to hear that the HP hose has a tiny prick :D

[@CephBirk]

Very interesting. Regarding the 50 bar zone, i have heard that this has nothing to do with SAC rate and more to do with the accuracy of the gauge. Any ideas on this?

[@Talor2]

Even so the video is somewhat older now... You said it yourself. With 50 Bar on the boat. So you actually would be fine. because the 50 would only be for your buddy and not for both of you. We If you plan a longer dive (eg 15l tank) with more gas you have more reserve if you do only a short dive (10l tank) you only need a shorter reserve. Thats what I learnd and it makes sense so far. But to know the calculation never hurts nobody so nice to see that.

[@magdit2001]

I've seen the glass of a pressure gauge fly of, so that is not a myth, they did not find the glass afterwards so it went quite far.

[@michaelthompson2764]

Most of the first 7 minutes to prove that SPGs can't explode when they can and do! I have pictures of a friend's that did explode and he was saved by his training. The fact that there is only a pinhole in the hose is irrelevant if the Bourden spiral leaks air slowly into the housing until it does explode. This video should be considered dangerous.

[@clarkeysam]

Rubbish! It's a brilliant video. The first few minutes show that SPGs SHOULDN'T expload the glass. This doesn't mean stare into the glass at close range but it certainly means don't point the blow out plug toward yourself and think you're safe.

[@slein55]

er den ikke lavet på dansk??

[@NOWDiveSkanderborg]

Nej denne video er kun lavet på Engelsk. Men hvis du har spørgsmål kan du altid træffe mig ved at kommentere her eller [e-mail]