Elite T3 recording depth change of 20+ feet in 2 seconds

[Gdon]

My Elite TS is set to sample every two seconds and it records a change in depth of 20 feet or more for one or two sample periods, several times on a dive. For example, in the below data export the format is dive time, depth, etc.. and as you can see the computer shows the correct depth of 40-41 feet but suddenly records 62 feet for four seconds. This also changes the NDL times. Anyone else seeing this? I assume this is a cause to return it for service?

00:33:20;42;4;0;(11-15);01:13;01:27;0:00;0;51; ;1;1490;Linked;
00:33:22;41;4;0;(26-30);01:14;01:31;0:00;0;51; ;1;1480;Linked;
00:33:24;40;4;0;>30;01:15;01:42;0:00;0;51; ;1;1480;Linked;
00:33:26;40;4;0;(21-25);01:15;01:42;0:00;0;51; ;1;1480;Linked;
00:33:28;62;1;0;(0-20);00:16;00:32;0:00;0;50; ;1;1440;Linked;
00:33:30;62;1;0;(0-20);00:17;00:30;0:00;0;50; ;1;1418;Linked;
00:33:32;41;4;0;(0-10);01:25;01:31;0:00;0;50; ;1;1408;Linked;
00:33:34;41;4;0;(0-10);01:26;01:31;0:00;0;50; ;1;1408;Linked;

And in the graph (attached) EVERY dark blue line up or down any distance from the main profile line is where the computer is reading the wrong depth (by a lot) for at least one sample (2 seconds)

 

[DiveNav]

it seems something is wrong with the pressure sensor. Get it tested.

 

[Gdon]

it seems something is wrong with the pressure sensor. Get it tested.

I don't think Aires tests them.. just replaces them. I could be wrong. I'll call them after I test it some more (with a backup computer beside it). I want to be sure of the situation because it is not under warranty and I will be paying for repair / replacement. :depressed:

I was hoping a Aires Rep would respond in the Aires forum.

 

[driftdiver24]

I sent my T3 back twice for this problem. Both times the service folks were very pleasant, but said tis a 1 in a million problem. Guess I should play the lottery because I had it happen twice and my buddy had the same failure, right out of the box on dive 3.

Next problem I had after repair 2 was lost link elevation errors. It would trip to an elevation dive at 1,500 feet, but not rest back to elv 1 until I went to 500 feet. Went back again, and was replaced.
Yesterday 30 minutes into the dive the link was lost and stayed lost for 15 minutes. Thank fully I’ve now stared to dive with a backup computer. Left the unit sit on shore with the computer attached to the BCD. Showing 000 psi for 10 mins. Then out of the blue it started showing pressure again. I’m waiting to hear form tech support on the latest failure.
Thinking its time to buy a UWATEC

 

[Gdon]

Thanks for that info.. it seems that the 1 in a million problem is pretty common after all. After I sent in my T3 because it was showing wrong depth in a small number of samples in the downloaded logs (and after I paid for an out of warranty repair), I received a replacement with a different serial number. Lo and behold, it is doing the exact same thing. It is set on 2 second sample rate and a few times on most dives the depth is way off.

Next dive I am going to put the computer in the BCD pocket (instead of on wrist) to see if it records bad depth readings that way.

I sent a message from their web site about three weeks ago but have not received a reply . I need to call them and will update this thread after that.

(Note to Aeris: I doubt you want this reputation. You should find out what is going on with these computers as well as respond to messages!)

 

[Gdon]

Update #1... Putting the T3 in the BCD pocket made no difference and it actually seemed a little worse on this dive. I'm sending my T3 in next week for replacement. If anyone wants to see what I am talking about you can download my log and load it into the Aeris software. Log file is at:
AerisLogFile - Windows Live

 

[Gdon]

Update #2:

I got my third Elite T3 with an earlier mainboard (serial #1010) and the latest firmware for that board (1H). After four dives I have not seen incorrect depth readings in the downloaded log.

To summarize, I had two Elite T-3 dive computers with serial numbers in the 2,000’s and latest firmware which showed occasional wrong depth readings in the downloaded logs (+/- 14, 24, 35, 37, etc. feet). These incorrect depth readings have not been observed on the dive computer itself but since there were only a few of them and they were only for two or four seconds at a time a diver would most likely not see it even if it was displayed on the dive computer.

As of now I do not have a satisfactory answer as to whether this error is only in the downloaded log, or is it an error in the dive computer that will also affect the calculations of NDL, ATR, Deco times, etc. The results of testing the DC should be available in another month or two.

The other thing myself and at least one other person has noticed was that the ending pressure reading showing in the Aires Interface (Log) on my PC was about 500-700 PSI lower than my actual ending pressure. In fact, according to the PC Log, I did the last five minutes of one dive with ZERO PSI! Ron at Tech Support explained this issue from his recollection of information he got from the engineers three years ago. As he recalled the issue is only with the Interface (logbook) software and not the dive computer. Something to the effect that when you download the dives it records changes in pressure readings and not the actual pressure, so if each change is a little bit off the error will be cumulative and show the greatest error at the end of the dive.

I assume this means the calculation of SAC rate in the PC log software will also be wrong which is too bad because that is one of the primary reasons I wanted an air integrated dive computer. Perhaps I will go back to manually calculating my SAC rate and comparing it to the Aires Interface (Log) number.

I am going to change the sample rate from every two seconds to 15 seconds. If the above is right then fewer samples should show less total error and my ending pressure in the log should be closer to actual pressure as shown on the dive computer (and SPG) at the end of a dive.