Are wireless transmitters junk?

[2airishuman]

I too have seen instructors dive without an SPG. There are obvious risks.

Off topic, if you have a good sense of pitch, you can determine whether a cylinder is full by tapping on it and listening.

We have been tracking transmitter failures relative to pressure gauge failures. Just had another pressure gauge failure yesterday. The gauge read 600 psi while totally empty. Last week we had one transmitter that was reading pressure intermittently. We had two high pressure hoses that were leaking.

In our unscientific study, it seems to be about even over the last two years. Anything man-make can fail.

Be careful. It's tempting to believe what you want to believe. Consider:

1. Are you including dead batteries in your hoseless AI failure count? Why or why not?
   
2. Does your population of divers have equal numbers of hoseless AIs and SPGs?
   
3. Are the SPGs in your population of divers the same age as the hoseless AIs? If not, what effect does this have on results?

I believe there are four important failures to consider:
1) The likelihood of an erroneously high reading during a dive, which poses a safety problem.
2) The likelihood of an obvious failure first detected during a dive, which should lead to the dive being called early.
3) the likelihood of a failure detected during predive checks, which should lead to the dive being cancelled or backup equipment used
4) The average life of the system, which has cost implications.

The SPG failures I have seen involve flooding, air leaks, or progressive stickiness or loss of accuracy, which only contribute to #4 as long as maintenance procedures are followed so the problems are caught early.

Do divers that use a pressure gauge carry a back-up?

Typically I carry a spare reg set that includes an SPG. If I have SPG problems before a dive, I can either swap SPGs, or just switch to my other reg set.

 

[Kevrumbo]

. . .The question now is, do I even use the wireless transmitter anymore? I know that redundancy is best but it seems like an unnecessary point of failure. Also, I could always rely on my buddy for depth on rec dives in the case of a standard SPG failure (which I hear is rare). What does DIR say about wireless transmitters?

DIR says you should motivated to learn what your SPG is going read in any five or ten minute interval even before unclipping and looking at it to verify:

Let's see . . .I have a full 200bar tank and consume 30 bar in five minutes at 18m depth:

Five minutes elapsed time and my SPG should read 170bar -check! It does.

Another five minutes for total Ten minutes elapsed time and my SPG should read 140bar -check! It does.

Fifteen minutes elapsed time and my SPG should read 110bar -check! It does.

Twenty minutes elapsed time and my SPG should read 80bar -check! It does,
and then start a multi-level ascent to the shallows & eventual safety stop. . .

You don't need the extravagance of an Air Integrated Computer to do the above easy iterative subtraction arithmetic.

I once had a 2005 Suunto Vytec Wireless Air Integrated: could never reliably get it to synch pre-dive; and when it did synch with my double AL80 cylinders, it would "time-out" and fail to register a reading if I wasn't breathing from my doubles (i.e. Breathing from a bottom mix stage cylinder or a deco bottle). Switched back to an analog SPG in bar units, and I haven't missed that fecal-piece-of-scat WAI transmitter. . .

 

[AJ]

Do divers that use a pressure gauge carry a back-up?

I don't. Do see the need for backup. If my SPG breaks I still can end my dive in a safe way.

 

[laikabear]

I have a Hollis DG03 with AI. The transmitter has not had a problem in ~ 80 dives. I have a backup SPG. I'm on the 2nd one. My first was a Suunto gauge that I got secondhand. It worked fine for about 60 dives, then one day was leaking air at the pre-dive check. I tightened the connection, and that stopped the leak, but the gauge read 300 psi too high after that.

I would have called that dive on the bench if I didn't have AI (which would have been annoying, because I'd assembled my gear that AM at home and pressurized the tank, and there was no leak then). I wasn't sure what the SPG was going to do. It turned out that it was very precise, just 300 psi too high at all times. I bought a new SPG and haven't had any further problems, but I like having both.

I get that a lot of people think AI is an unnecessary expense. But provided you have a backup SPG, I don't see how AI is hazardous, which seems to be the opinion of some.

Had to take the transmitter off for GUE Fundamentals though.

 

[tridacna]

Scubapro......ain't anymore. It was bought out by Johnson and Johnson a long time ago.

Really? The Band Aid company? You sure?

 

[Neilwood]

I am in the process of looking at an AI computer and I would use the pod in conjunction with an SPG..

My reason - why the hell not? For the cost of a brass and glass SPG, I might as well have the back up there if there happens to be any issue with the AI syncing. Loss of connection means I can still continue the dive.

If I was only diving with the SPG (as I do now with it integrated into a two part SPG/ depth gauge console), I would treat that failing as a dive ending event and proceed to the surface in an orderly fashion (making my buddy aware of the failure and that I don't know how much gas I have left).

 

[tridacna]

After three misfires on three boats with my Galileo (and three missed dives), I moved to a Cobalt with a brass and glass backup. No more WAI for me. It's not worth it to save one hose. I was on a boat in Bermuda recently and watched a diver have two failures with two different Lunas. Her first one failed to sync; "No problem", she said, "my son's computer is in my bag as a backup". That one failed to sync too. No more hilarity. She decided to dive anyway with no pressure gauge. Followed her husband's guidance because "she breathed better than him". She surfaced after 30 mins. I would have thumbed it.

 

[BoltSnap]

After three misfires on three boats with my Galileo (and three missed dives), I moved to a Cobalt with a brass and glass backup. No more WAI for me. It's not worth it to save one hose. I was on a boat in Bermuda recently and watched a diver have two failures with two different Lunas. Her first one failed to sync; "No problem", she said, "my son's computer is in my bag as a backup". That one failed to sync too. No more hilarity. She decided to dive anyway with no pressure gauge. Followed her husband's guidance because "she breathed better than him". She surfaced after 30 mins. I would have thumbed it.

This is very strange, the Galileo (both versions) are some of the most stable and reliable AI computers out there. They have been on the market for a while and are stable. I have several friends across several continents who use them no issues at all.

 

[fmerkel]

Really? The Band Aid company? You sure?

No, sorry. Johnson Outdoors. Knew it had something to do with Johnson. Should have verified that before spouting off. But, problem remains, it's not the same company it was. A significant portion of their design and engineer staff left after the merger.

From the wiki:
Scubapro
Scubapro was founded in the United States in 1963 by Gustav Dalla Valle, Beuchat representative in USA and Dick Bonin to manufacture scuba gear. The "S" logo was adapted from the Beuchat “Souplair” regulator. In 1966 Scubapro introduced the first analogue "decompression meter", a forerunner of the dive computer and created the first "stab(ilizing) jacket", a vest-type buoyancy compensator, in 1978.

Scubapro merged with dive computer manufacturer Uwatec in 1997 and became part of Johnson Outdoors. The company, now known as "Scubapro Uwatec", currently manufactures diving regulators, buoyancy compensators, dive computers, masks, fins, snorkels, wetsuits and drysuits, as well as scuba accessories.[7]

Uwatec
Uwatec was founded in Switzerland in 1984 as a manufacturer of scuba gear. In 1987 it introduced the Aladin PRO, establishing a reputation for making diving computers; however, multiple lawsuits accusing Uwatec (and later Johnson Outdoors) of a seven-year cover-up of a potentially lethal dive-computer bug tainted that reputation.[8][9] Uwatec merged with Scubapro in 1997, becoming part of Johnson Outdoors.[7]

 

[dumpsterDiver]

I have NEVER had a transmitter fail - EVER in several thousands of dives...

Of course, I know better than to spend my money on something like that.