Verifying depth calibration?

[CuriousRambler]

I have an Aladin Tec2g, which I bought new some years ago. From new, I've noted multiple dives where my depth reads ~10-15ft deeper than my buddy's. This has happened with at least a half dozen buddies in even more dive locations. Analog or computer, obviously different gear with each buddy. I recently had a Scubapro dealer replace my battery, under the understanding that pressure pot calibration is part of that service. When I picked it up, the employee I dropped it off with and the service guy were both off, and the employee working wasn't willing to comment beyond "if they were supposed to do it, I'm sure they did." I'm still seeing disagreement on depth, things that can't be explained by different dive profiles, like we both check out a big puffer on the sandy bottom, getting within a few feet. At no point was it physically possible to go more than 2-3 feet deeper than we did, but my max depth is 13 feet greater. Yes, both computers are set for salt water in the latest case. Others, I can't speak confidently for others.

How can I verify this? I'm open to building a pressure pot, but have too many projects already so it wouldn't be soon. It's not so far off I'm concerned about safety, and if it's erring on deeper than reality, I'll call it extra conservative. More curious how to check it, and if I can fix it. Or do I need to start a piggy bank for a new computer?

 

[lermontov]

check again for what density settings or maybe altitude on auto? it could be depth sensor is toast

 

[NAM001]

I was going to suggest altitude but lermonto beat me to it. being 13 ft off is like almost 1/2 atm or about 12000 feet of altitude. If that were the case it smight be off the same amount I would at all depths.

 

[CuriousRambler]

I have noticed the altitude setting varies on its own. I almost exclusively dive in the ocean, so I've reset to 0ft altitude several times. Every time I look at it, it's back at 400-500, sometimes less, but never zero. But it's also minor enough I can't see 15ft depth coming from it..

 

[DIVEWATCHDOCTOR]

CuriousRambler,

If you send us your Aladin Tec2g, we could waterproof it to 160 feet and check your computer depth reading vs. our Bergeon calibrated pressure gage (check our avatar) every 20 feet and report the results back to you. It would cost you $ 25 plus return shipping. We DO waterproof to 160 feet and verify depth accuracy of every dive watch or dive computer we service. However, I should warn you that if when we calibrate your computer it shows a consistent depth difference of 10 or 15 feet, your computer can not be recalibrated. Visit our website: www.divewatchdoctor.com

 

[michael-fisch]

Unfortunately sounds like your Tec2g is toast. Don't believe that it can be repaired, but
sending a nice letter to Scubapro USA detailing your problems might help them decide to give you a major discount on a new replacement computer.
Give it a try.

Michael

 

[Dark Wolf]

Following this thread. I recently retired two old Dive Rite computers. Depth was off on both. One read shallow, one read deep.

DW

 

[jale]

Following this thread. I recently retired two old Dive Rite computers. Depth was off on both. One read shallow, one read deep.

DW

So just take both and do "averaging"

 

[Seaweed Doc]

Have you ever compared depth with your buddy during the dive?

My AL i300c and Perdix consistently agree, but my students' rental gear computers are often off by 5-6 feet from mine. (In OW in our first dive to 60' I have them check and show me their computers at 58 feet.)

 

[Dark Wolf]

So just take both and do "averaging"

I always wear 2 computers, and that is exactly what I did until the Nitek Trio finally died.

DW