PSI Gauge when breathing

[RenaM]

Is it normal for your PSI gauge to drop around 500 PSI when you take a breath?

I was using some rental equipment on a vacation, and the gauge would drop 500+ PSI whenever I took a breath. I never noticed this before on other PSI gauges, so it made me freak out a little.

I was to inform the dive master when I was 1,000, but I kept on showing him the gauge because when I breathed out, I was 1,000, but breathed in I would be at 500.

 

[tplyons]

Nope, not normal. Are you sure your valve was open all the way?

 

[rhwestfall]

Tank valve opened all the way?

 

[WheelsUSN]

That is usually an indication that the tank valve is barely turned on.

 

[wjeiii]

That is usually an indication that the tank valve is barely turned on.

Or the regulator filter is clogged. Always look at the filter when renting a reg.

 

[Steve_C]

That is a big no-no. There is a problem somewhere between you and your air supply. Usually the tank not all the way on. However, there could be something else wrong too. If you go deeper it could get worse. Last thing I do before going in is to take a couple puffs on the reg. If it moves, I will not go in until fixed.

Depending on depth and work load this could be life threatening.

----

I will rent wet suits, fins, bcds, and lots of stuff when I travel. But my prescription mask, regs, and computers are almost always my own.

 

[herman]

Another possible cause is you were using a J valve and it was in the "dive" position. It's highly unlikely that you would get a J valve as a rental but I assume it is possible. If it was a J valve and it was in the "dive" position, then that is normal operation for them. Most people who still use them just dive them in the "reserve" position unless they are actually using them the way a J valve was intended. Few people still use them and even fewer still are trained on how they operate.
Otherwise I agree with the rest, it was an almost closed valve, clogged reg filter or a clogged dip tube. In any case if it was not a J valve in the "dive" position then there was a problem and it's not normal.

 

[RenaM]

Thank you for all the replies. I should have insisted something was wrong. But when I talked to the dive master, he didn't completely understand my English (we were in Costa Rica) and he basically ignored me and categorised me as a nervous diver (which I am to a degree).

I never checked the tank value, I kick myself for forgetting to do this. I'm trying to be a better diver, but I only have about 10 dives so far and still learning.

Thank you again everyone.

 

[tursiops]

Before a dive:
1. Look at the pressure gauge, it should show "full tank." THIS IS NOT ENOUGH, DO NOT STOP HERE!
2. Take three good breaths from the reg....if the pressure goes down and stays down, the valve it turned off. Turn it on and go to step 1.
3. If the pressure swings down, then back up, mostly likely the valve is only barely on. turn it on and go to step 1.
4. If the pressure gauge doesn't move when you breath from it, go diving. Otherwise, call the dive.

People will tell you to turn the valve all the way on, then back slightly, maybe 1/4 turn. There are historical reasons to do this, but in general it is not necessary. People will disagree with what I just said! OK, fine, so why do tech divers NOT do the 1/4 turn back? (Actually, people will argue about this, too, but my point is that turning it full on is not life-threatening.)

Make those 3 breaths before going in a standard part of your routine, like putting your face-mask and fins on.

 

[TMHeimer]

Yeah, you don't want to just turn your air on a little. I noticed a student did this when we were doing the Out of Air skill. Not sure why one would only turn it on a little. Other stuff can happen as well. I had to replace my SPG because I noticed the needle would go down as normal but then get stuck on 1000. This was not at all a good thing....