How reliable is the Suunto Transmitter?

[JohnN]

From what I can recall, the indication disappears

This behavior shouldn't surprise you. . . You know the transmitter is activated when it "see's" a pressure change from low to high, and is deactivated when the pressure drops below a threshold.

The fact that it won't read tank pressure below 15 bar (about 220 psi) seems entirely reasonable to me.

Perhaps you should rethink your methodology for testing the accuracy of the pressure transmitter

 

[gogotsu]

Well, I don't think it is reasonable that it indicates 30 bars when there are only 15 left or maybe 50 when there are only 35. I would understand that it stopped indicating anything under 15 but not indicate 15 when you can't even breath at all from the regulator ( I tested this at a depth of 2 meters). Anyway, the indication is not always 15 above; as higher levels the difference is smaller but always above.

 

[JohnN]

Well, I don't think it is reasonable that it indicates 30 bars when there are only 15 left or maybe 50 when there are only 35. I would understand that it stopped indicating anything under 15 but not indicate 15 when you can't even breath at all from the regulator ( I tested this at a depth of 2 meters). Anyway, the indication is not always 15 above; as higher levels the difference is smaller but always above.

Wouldn't a better test be for you take your tank to your LDS and have them check the pressure with a quality digital gauge. Then put your 1st stage and transmitter on the tank and compare the readings. Right now you're comparing an unknown with another

 

[gogotsu]

I haven't got a tank of my own, so that is really out of the question. And what I know for sure is that the transmitter is giving wrong information, as it indicates that there is still air pressure when there is not. The spg, on the other hand, seems to be right, although you can never know exactly, as the lowest indiction of the needle is 10 bar and it can not go further down. But when it reaches that point I still have some air and a little after that there is absolutely none, which makes me think it is quite accurate. I was really expecting the transmitter to be the most accurate of the two, as it is also mucho more expensive. I also think it would be better if it indicated that there is no air when there is still some and not the other way round; it would make it much more reliable.

 

[TheReefDiver]

Recently my analog spg's needle got stuck so I just decided to ditch it all together. The DMs I dive with insist that I should always have an spg -telling me stories about how unreliable wireless transmitters are and how often they've seen it fail. I've been diving with my Suunto D9tx for a little over 4 years and I never had any problems with it. I change the batteries on both watch and tx (transmitter) every 2 years regardless of whether or not I get a low battery warning to ensure it won't quit on me mid dive. I don't do wreck diving and I rarely go deeper than 90 ft (30 m). I always dive with a group of 3 or more and I never stray away farther than 20 ft. I'm fairly efficient in my diving that I usually come up at 1100 - 1300 psi when the rest of my group is at 600 -800 psi.

So how reliable is the tx and how unsafe am I to ditch the spg? Worst case I can think of is tx failure in which case I'll just safely ascend and abort the dive, grab my tools and rent an spg. I really highly doubt it, but would it be possible for the tx to give me a false reading of more than 600 psi and result in cutting out my air?

Hi Chris,

I have a Suunto Vyper Air (2yrs old) and a transmitter (9 months old). My unit will sync normally at start of dive then a few minutes in I get the fail at depth, then magically it turns on again, then off again, then on again till the end of the dive...does not matter the depth etc.. I have all the dives logged. Both items have new batteries - I did not need to do the transmitter but I wanted both of the units to be on the same maintenance schedule - every two years...I dive about 35-50 dives per year. I have resorted to putting my console back on but this is not what I signed up for...I would have just bought a cobra 2 / air. btw - I have had intermittent readings of 4500psi (bogus) out of the blue as the other user on the thread has had.

Please advise.

Dean

I have recently went on a liveaboard with my D4i and transmitter. Starting from the first dive, at some point during each dive, the computer suddenly started to show 5 bars, and then go down from there to 0. I did not care much about that because my air consumption was best on the boat, but it raises a reliability issue. After a couple of days I hired an additional pressure gauge to be on the safe side. I have the computer for two and half years with roughly 100 dives and a recent battery change, and the transmitter a bit more than a year with around 50 dives. No indication of a low battery, neither of the computer, nor of the transmitter. Seems similar to Dean's scenario.

I also have a cobra that I bought in 2010. On the first dive trip it also started to give wrong indications of the pressure. I got it replaced after 20 dives, and the new one works perfectly since then. Anyways, it make me suspect that Suunto may have a problem with the pressure unit rather than the wireless. On the positive side, an EON that I bought in 1994 still functions perfectly

 

[tdarko]

I know this thread is getting up there in age, but maybe somebody will check in and see this.

I think I had both of these issues this past weekend. Before our first dive I got all my gear set up, paired my Vyper Air and transmitter, then as we were getting ready to get in the water, I got the always fun FAIL signal. I may have moved too far away from the regulator or just taken too long getting ready - we had a pretty complicated shore entry. I tried to put the computer next to the transmitter to get it to reconnect, pulled a few breaths, inflated and deflated the BC - nothing. Went through the pairing procedure again, switched from channel 37 to 31, and had no problems from then on.

But I did notice something interesting during the dive and I'm wondering if anyone else using a Suunto AI has ever noticed this: When I would put the computer until compass mode, the tank pressure would only update every 20-30 seconds instead of instantaneously. It said FAIL for a very short time during one of our dives (I can't remember if it was the first or second), but reconnected within a minute. Visibility could be described as just short of abysmal - maybe 2-5 feet at most times, and we were less to 20 feet deep. When I would switch back from compass mode to normal dive mode, the tank pressure would very quickly drop over the next few seconds, presumably just getting the computer's reading back in line with what was really in the tank. I didn't happen to notice if the air synch indicator on the left side of the screen was blinking during compass mode or not. When I uploaded the dive information to my desktop at home, the air pressure follows a predictable, regular negative slope from start to finish, indicating that each 20 second time point it was at least keeping track of the pressure. There was one exception, which may have been related to the brief FAIL, when the pressure stayed steady for a minute and twenty seconds, then dropped sharply before returning to the normal curve.

Has anyone else noticed this when using a Suunto computer and AI? Specifically if you have a Vyper Air. It seems that it keeps updating at least at the same interval that it collects data (I changed it to 10s intervals yesterday, but I haven't done a dive with it yet), so I'm thinking that when the computer is in compass mode, it just has too much to think about for it to connect to the transmitter constantly and it just drops the rate to whatever interval you have set. I might be looking at my computer a little too often and getting nervous that it's going to fail on me because it's new, I'm new to diving (9 dives so far), and I'm not a fan of drowning. I'm just hoping for a little confirmation that this is normal for the Vyper Air and not something I need to be worried about.

Thanks.

Hi,

I have experienced almost the same situation.

I have Vyper Air computer and Suunto wireless transmitter. Yesterday, I did some training for navigation module of AOWD, and my computer was all the time (1:05h) in compass mode. Also, I recorded cca 15 bookmarks in the same compass mode.
At the very end of my dive, I noticed that my pressure readings was 140 bar, then 230, even 250. After one minute, it went back to normal 67 bar.

Can someone else also confirm the same bug with compass mode, bookmarks and wireless transmitter?

Best regards,
Darko T.

 

[Macan]

The Suunto Transmitter is "fairly reliable" with a few annoyances that can render it useless if you're not careful.

Note that this is in Tec Doubles and on Tec dives. I connect the Transmitter in my Right Post and a standard SPG on my Left Post in doubles. The benefit of this setup is the ability to still have back gas pressure reading with a shut-down left post. But the biggest advantage of a Transmitter use during Tec is the convenience and ease of checking your back gas pressure with a simple flick of the wrist. Very handy particularly in overhead environments while carrying two deco bottles on the left side. Obviously counter checking with the SPG regularly is a given.

Transmitter Annoyances:

1. If you forget to sync the Transmitter with your Suunto computer or, if you sync but allow it to time out after a several minutes before you hit the water, you will not have any gas pressure information. This is really annoying. Solution is to always check and re-sync the transmitter if necessary before descending. You can't re-sync while underwater.

2. If you shut down the right post (where the transmitter is attached) underwater during a Valve Drill, when you turn the right post back on, the Sync is broken and you will no longer receive pressure reading. You can't re-sync underwater.

3. During Deco Stops when you do a gas switch, the Transmitter on your back gas is idle. It will time out after 30 minutes (to save battery). Deco stops are long. Solution is to purge your primary or secondary reg or take an air break every 25 minutes (as you should) during Deco. Doing this will reset the idle time and allow the transmitter to continue sending back gas pressure reading to the Suunto D9.

4. I use a Petrel 2 as my primary DC and the Suunto D9 as backup. Both are on right arm. If the Petrel is too close to the Suunto, there is signal interference and the Suunto pressure reading will "Fail". Solution is to move the Petrel further up the arm by an inch or so and all is well.

Despite these annoyances, I find it convenient to just "flick your wrist" to check your back gas pressure. That's the big advantage of an AI. The good thing is either you're getting a pressure reading, which is very accurate, or not receiving a pressure reading at all and the DC will display "Fail".

 

[pinshootr]

put a button gauge on your 1st stage, you can always roll out of your BC and check it in case of failure

 

[BoltSnap]

4. I use a Petrel 2 as my primary DC and the Suunto D9 as backup. Both are on right arm. If the Petrel is too close to the Suunto, there is signal interference and the Suunto pressure reading will "Fail". Solution is to move the Petrel further up the arm by an inch or so and all is well.

Don't these two computes have two different deco algorithm and will give different deco information from each other? If so, isn't that going to be a problem when one is giving more deco time, or less, than the other? Also, the D9 wasn't really meant for technical diving AFAIK, isn't this an issue for you when doing technical diving?

 

[Macan]

Don't these two computes have two different deco algorithm and will give different deco information from each other? If so, isn't that going to be a problem when one is giving more deco time, or less, than the other? Also, the D9 wasn't really meant for technical diving AFAIK, isn't this an issue for you when doing technical diving?

Yes, the D9's algo is RGBM while the Petrel is on ZHL 16c GF. The D9 works well as a non Trimix Tec computer. It's a multigas computer capable of 3 gas switches (which is all you really need for most deco dives) up to 100% O2 sans Trimix. The D9 is actually more liberal than ZHL 16c with GF 40/70-75. It clears sooner. So the D9 serves as a good Get-Outta-Dodge backup if the Petrel fails. I also use a wrist slate on the left arm for a written deco plan.

My view is a having the same identical computer as a backup is not a good idea. They may both fail at the same time due to the same SW/HW glitch. Having a different and more liberal computer as a backup works well. If you need to get out of the water fast, that's your ticket.