Verifying depth calibration?

[CuriousRambler]

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

Not recently, but I have in the past. After I noticed differences in our max depth post-dive, I compared with a couple others during the dive and was deeper. Can't recall by how much, but I did log the comparison and said my computer was deeper on two occasions with different buddies. One of those comparisons was a buddy with an analog console and a wrist computer, which agreed with each other, leaving me the odd man out.

 

[D_Fresh]

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..

Could this be the result of the barometric pressure changing (i.e., weather coming in) and the computer "seeing" that as a change in altitude?

 

[michael-fisch]

Could this be the result of the barometric pressure changing (i.e., weather coming in) and the computer "seeing" that as a change in altitude?

350 to 450 millibars or 5-8 psi? No!
Not even the eye of a major hurricane has that much change.

Michael

 

[CuriousRambler]

350 to 450 millibars or 5-8 psi? No!
Not even the eye of a major hurricane has that much change.

Michael

I suspect he was referring to the varying elevation setting I see on the surface, in which case my best guess is also just some auto setting varying with weather patterns, which would be more like 0.2-0.3psi, or 0.6inHg which is well within the range of most weather barometers.

Definitely, the depth issue isn't that far off because of some clouds haha

 

[D_Fresh]

I suspect he was referring to the varying elevation setting I see on the surface, in which case my best guess is also just some auto setting varying with weather patterns, which would be more like 0.2-0.3psi, or 0.6inHg which is well within the range of most weather barometers.

Definitely, the depth issue isn't that far off because of some clouds haha

Yes, that's exactly what I was referring to. I should have expanded upon it in my previous post. But back in Arizona, during summer monsoons, I have definitely seen my GPS's barometric altimeter rise a few hundred feet elevation as a storm rolled in... So if the OP's DC has an "auto elevation" feature using barometric pressure, I could see it being possible for the computer to make such a mistake...

Maybe @DIVEWATCHDOCTOR can chime in as to whether or not that is actually a possibility in this case...

 

[Blackcrusader]

My Perdix at 3275m altitude or 10745 feet

 

[dmaziuk]

... back in Arizona, during summer monsoons, I have definitely seen my GPS's barometric altimeter rise a few hundred feet elevation as a storm rolled in... So if the OP's DC has an "auto elevation" feature using barometric pressure, I could see it being possible for the computer to make such a mistake...

The Fine Manual says 2G has an "altimeter", samples "altitude" every 60 seconds even when the display is off, and automagically resets its altitude.

 

[Searcaigh]

The pressure sensor could be the problem.

I had to retire my Suunto HelO2 a couple of months ago which I used in gauge mode strapped to one of my flat arms on my camera housing. I liked the large font on it, anyway I still rely on Shearwater for my dives.

 

[Dark Wolf]

The pressure sensor could be the problem.

I had to retire my Suunto HelO2 a couple of months ago which I used in gauge mode strapped to one of my flat arms on my camera housing. I liked the large font on it, anyway I still rely on Shearwater for my dives.

I figure that is exactly what is wrong with mine, and the OP's.

DW

Edited for spelling

 

[Bob DBF]

I’d first call and have a talk with tech that worked on it, and find out what he found when working on it.