POLL: SPG or transmitter failure - UPDATED TO BE EASIER

[Bigbella]

The only "failures" that I have ever experienced with SPGs, over forty-five years, and thousands of dives, were related to spools or outright hose failures, which only required a couple of minutes to replace and never with the gauge head themselves. Still have a few nearing forty-years old, scratched up as all hell, but still usable.

I am only a recent adherent to some transmitter use, some five hundred or so dives, but always carry an SPG as well; and a full analogue set in my save-a-dive kit.

In that time, I have had two outright transmitter failures and a few incidences of intermittent signal interference, six or so, with loss of information; and two full replacements from the fine folks at Shearwater in the Great White North . . .

 

[stuartv]

I don’t even know how many SPG’s I’ve had to replace, not zeroing and spooled being the most common issue, they tend to get beat up hanging on that hose, one of the reasons I screw transmitters into the first stage.

I had one transmitter quit on me, an older SP type with the 2450 battery, no idea what went wrong because I just replaced it. I only dive wireless air integration for the past several years, SPG is rolled up in my SAD /tool kit but the only time I’ve used it in several year is when I forgot both computers at home.

The one transmitter I had that died was a Shearwater-branded PPS one. I learned after it died and Shearwater (Dive-tronix) replaced it at no charge, that there was a bug in the PPS transmitters - at least, some of them - that *could* crop up whenever you changed the battery. If it did happen, when you put the new battery in, the internal processor would go into some kind of loop, stay on, and run the battery until it died (which didn't take long). It would also get pretty hot on the outside.

Putting a new battery in mine did not fix it. I do not know, if I had realized what was happening and take the new battery out and put it back in again quickly, before it really got hot, if it would have started working again.

Anyway, I haven't had the issue happen since.

The good news is, if that does happen (that the transmitter goes into a death spiral as soon as you install a new battery), it will probably be dead before you ever splash, so you notice it and do not end up having it die or noticing that it is dead during a dive. In my case, I put in a new battery and splashed shortly after. Mine was still working for the first couple of minutes of my dive.

 

[Wants2divemore]

Another question that is not accommodated is "how many dives did you do where you only found out afterwards that your <SPG/AI> reading was significantly inaccurate?" For example, your SPG stuck at 700 psi and you never realized it during the dive, even though you exited with 300 psi.

On the other hand, this is a very real failure mode for SPGs. A needle that sticks and - for example - says 1000 when you really only have 500 is not that common, but failures of that type do happen. And those are (in my opinion) the most dangerous type of failure (of an SPG/AI) transmitter you can have.

The survey doesn't have a way to capture the data on that type of failure, I don't think - and it's a very important piece of the underlying analysis being performed.

I agree this is a very important type of failure. I assumed, perhaps incorrectly, that people would be checking their SPG enough to realize a stuck needle during the dive. I'll modify the survey to include this.

If anyone who has already completed the survey has had a stuck needle SPG failure that they discovered after the dive but didn't count it as a failure because of the survey definition of failure, please let me know.

Thanks everyone for your comments and discussion. I appreciate them.

 

[blatter]

1) 4500
2) 3
0)
0)

I wouldn't classify a leaking spool as a failed spg.

Two failures were the spg showing a fair bit of air when there was about zero - stuck needle - something I check for regularly. The other was a burst HP hose - again I check condition of hoses regularly - was using independent doubles on that dive so just turned off the valve to stop the annoying bubbles while I completed the dive.

My failure rate is actually much better than 3/4500 dives - there are lots of dives I have done which I have not logged and lots of my dives are done using multiple cylinders each with their own spgs (ccr, pony, deco gas, doubles etc).

 

[Wants2divemore]

I just realized that I forgot to explicitly state that a couple of days ago I created a Survey Monkey poll and modified my original post to link to the new survey. So, if you've been reading this thread from the beginning and didn't reply with the answers to the 4 questions I asked, I'd appreciate it if you would answer the brief 4-question survey at the link below. Thanks.

SPG / Transmitter failure survey

www.surveymonkey.com

 

[Belzelbub]

I agree this is a very important type of failure. I assumed, perhaps incorrectly, that people would be checking their SPG enough to realize a stuck needle during the dive. I'll modify the survey to include this.

This is exactly the failure I had. Wasn't using my gear, I was using an aquarium's gear. In a normal dive, I would have ended it and gone up. I knew from previous dives that I had well over an hour. Dive was quite shallow (less than 20') and I had a Spare Air. After about 10 minutes and many thumps of the SPG, it did start reading again.

I did respond to the poll and counted this as a failure, as it would have ended a normal dive.

 

[Wants2divemore]

Thanks to the 50 who've responded to this survey about SPG / transmitter failures. I'd like to get as many responses as possible before I post the results. If you haven't completed the survey, it's just 4 short questions.

SPG / Transmitter failure survey​

Thanks.