Checking for fluctuation with transmitter?

[grassybreakfast]

Hello!

Recently acquired an Aqualung i770R with transmitter, so I'm very excited, and been thinking about removing the SPG to reduce clutter once I have some confidence in the transmitter's reliability (I've read the various threads on this topic, and decided that I'm ok with having to abort a dive if the transmitter fails, assuming it happens very rarely).

However, one thing I'm worried about is not being able to do the "needle fluctuation check". I'm not sure how common it is, but in training (BSAC OD + SD) we have always been taught to do a few fast inhales and check for needle fluctuation on the SPG (which would indicate the valve not being fully open). Is that still possible with a transmitter? Or do people just not do that? It would still work if the transmitter can transmit the lowest pressure seen since the last sample time, but I'm not sure if that's how they work.

Thanks

 

[Jens Bölte]

Hello,

I usually don‘t do a ‚needle fluctuation check‘ with a transmitter but I can tell you from experience that you would see a not properly opened valve

Best wishes Jens

 

[grassybreakfast]

Hello,

I usually don‘t do a ‚needle fluctuation check‘ with a transmitter but I can tell you from experience that you would see a not properly opened valve

Best wishes Jens

Can you elaborate on that please? How would you see it? I am very new and have not encountered that in real life.

 

[Marie13]

Can you elaborate on that please? How would you see it? I am very new and have not encountered that in real life.

Do 4-5 breaths. I’m of the opinion you need to be more than 2-3 breaths to see any issues n

 

[grassybreakfast]

Ah I see so you would just try to detect difficulty breathing?

 

[Belzelbub]

Not a huge issue, and seems to be a remnant of earlier days. When it was a good idea to partially close the valve.

My valves are either fully opened or fully closed. Taking a few breaths off of a closed valve will become quickly apparent as the pressure drops rapidly.

 

[Tracy]

It will not work with a transmitter, they do not respond fast enough. Just reach back and double check your valve is all the way open.

 

[grassybreakfast]

Not a huge issue, and seems to be a remnant of earlier days. When it was a good idea to partially close the valve.

My valves are either fully opened or fully closed. Taking a few breaths off of a closed valve will become quickly apparent as the pressure drops rapidly.

Thanks for the reminder. I was taught the quarter turn back a few years ago when I did my OD, and have been doing it since without questioning. Because of your post I did some research just now and will stop doing it from now on

 

[Marie13]

Thanks for the reminder. I was taught the quarter turn back a few years ago when I did my OD, and have been doing it since without questioning. Because of your post I did some research just now and will stop doing it from now on

People are still teaching that?!

 

[Belzelbub]

Thanks for the reminder. I was taught the quarter turn back a few years ago when I did my OD, and have been doing it since without questioning. Because of your post I did some research just now and will stop doing it from now on

Good to hear. Unfortunately, it’s still taught today. Should have died out long ago. Currently it serves no real purpose, and only serves to create confusion as to whether the valve is mostly open, or mostly closed, as the valve can move in both directions.