Aeris Computers

[liquidvisions]

This is a copy of an email sent to Mark Lane with no responce.
I recently sent my Aeris XR2 wrist computor to you for repairs, it dives while on the surface and does not allow me to dive it, you replaced the computor.
The replacement is now doing the same thing, it does dives to 8ft while on the boat and then eventually shuts down and goes into an Alt mode and it takes days to be able to use it.
I am an instructor and rely on my computor for my safety and the safety of my guests, I have an Atmos 2 and an Elite computor sittting here at home that have all experienced the same problems and I have become so frustrated that I have set them a side and do not use them.
Before working on Saba my wife and I owned a dive shop in Canada and were Oceanic, Aeris dealers and really loved your products and promoted them. I have 2 Aeris regulators sitting in my home that I no longer use because I can't get kits even though I am an Aeris trained reg tech.
I am interested in any feed back and an expanation of what is going on with these computors

 

[bperrybap]

Here is my only possible guess...
Do you happen to store the computers in a waterproof dry box like an otter box or perhaps one of the Cetacea save-a-dive box?

Those boxes are not only water tight but air tight as well. Once the box is closed, the pressure inside the box will vary with temperature.
If the temperature goes up the air pressure inside the box will increase and if the temperature goes down the air pressure inside box will decrease.

Also, I've seen that my boxes tend let excess pressure out but not back in.
So if I take it on a flight, it will let the ground level air pressure out to equalize
with the cabin pressure (which is only pressurized to about 7000-8000 feet).
Once back on the ground, the pressure does not equalize and so remains
in vacuum with respect to ground pressure. (assuming you didn't land in Peru).

I have seen this pressure remain in vacuum for days. It is actually somewhat
difficult to open the case until you breach the seal and let the pressure equalize.

What is interesting about the 8ft depth number is that the difference between pressure
on the ground and at 7000-8000 ft, which is a pressurized plane, is a bit under 4 PSI
which happens to correspond to about 7-8 ft of depth in water.

If the computers were stored in box and that box has a pressure differential relative to the current air pressure, when the box is opened the computer will potentially
see a rapid pressure change and might make an incorrect assumption.
If pressure in the box was enough below current barometric pressure, then the computer might think a dive started.
If the pressure in the box was higher then the computer might think the computer
suddenly went up in altitude.

The Xr2 manual states the computer samples the air pressure (which I am assuming uses the same pressure sensor as the depth sensor) every 30 minutes
when not wet (even when power off).
It samples pressure immediately when manually activated to compensate for
altitude.

What is not defined is what it does if the pressure suddenly changes but the
contacts don't get "wet".

My guess is that if the pressure suddenly increases by more than a certain amount,
it assumes that this is from going underwater rather than a sudden drop in altitude.


You can also see the mysterious "diving under land" phenomena on many
dive computers if you activate the computer on the airplane which normally is only pressurized to ~8000 ft
rather than ground level.
As you descend many computers will start to read a depth. So when you are back on land
after the flight, the computer will show a depth and be "diving".

The computer might also get confused if the computer is activated (on) and then put
into a sealed box that then gets warmer. The computer will now see the
pressure increase but it isn't getting wet.
If the pressure rise is slow enough it may assume you are driving to a new
dive location that is at altitude. Then when you open the case, it will see a sudden
drop in pressure and might assume you just jumped into the water.


================================

If you don't keep the computers in dry box. Well, I've got nothing.......


--- bill

 

[sanjac]

Thanks for the info. I haven't had this problem, but it is good to know. I store my electronic and camera gear in pelican cases. I'll be sure to depressurize as soon as I hit the ground so it has time to adjust.

Jim

 

[ianr33]

bperrybab,interesting post.

Presumably taking the battery out for a few seconds would fix it if that is the case.

I had an Aeris computer that started behaving strangely once. The shop I bought it from exchanged it and it has been fine for the last 5 years or so.

 

[NCadiver]

What kind of Instructor are you
"I am an instructor and rely on my computor for my safety and the safety of my guests"

Either your guest have thier own dive computer or they use the dive table not you computer for thier profile. And that in all dive computer manual and open water books as well.

So did you send Mark a copy of your Aeris certificate, and you should have bought all the kit you need when you were a store.

Your computer may have a pressure transduce problem since its diving at see level.