Will Air Integration in dive computers replace the SPG?

[dmaziuk]

I just made that up. It sounded good, don't you think?

I like seeing a needle move, observe how it responds to variables like depth and activity level. It involves the observer in the same way that an analog watch or oil pressure gauge does.

Mmm... I would use something like "gradient" instead of "level" myself.

You can trivially program a colour screen to show e.g. a green-yellow-red segment bar and wrap it in a circle if you like. Segment LCDs are a bit harder, I think aeirs had colour leds on the side of a300 for ascent rate indicator. What's left, then, is the polling rate -- I expect it to be on the order of seconds these days. Maybe tens of seconds. How often do you check your needle?

 

[agilis]

Mmm... I would use something like "gradient" instead of "level" myself.

You can trivially program a colour screen to show e.g. a green-yellow-red segment bar and wrap it in a circle if you like. Segment LCDs are a bit harder, I think aeirs had colour leds on the side of a300 for ascent rate indicator. What's left, then, is the polling rate -- I expect it to be on the order of seconds these days. Maybe tens of seconds. How often do you check your needle?

Depends. I generally check the SPG every 10 minutes or so, except when I'm making significant changes in my level of activity (not gradient) or going much deeper, when I might watch it continuously for a few seconds and then check it every couple of minutes for a bit.

This is especially the case when I'm doing some live fish collecting, a sudden and strenuous activity that can have me going through as much gas in two minutes as I did in the previous ten.

I did all my early diving with a J valve. I'd check the rod to make sure it was in the up position so frequently that 40 years later, when diving around close structure, I still sometimes find myself automatically reaching my left hand behind me to make sure the actuator rod has not moved.

 

[undrwater]

For the "needle" to jump during a restricted breathing test, the polling should be in the tenths or hundredths of a second range I believe.

 

[agilis]

For the "needle" to jump during a restricted breathing test, the polling should be in the tenths or hundredths of a second range I believe.

I'm not sure I understand. I monitor the 'needle' (I try to avoid techterminology) over time to see how rapidly it is moving, how rapidly the gas is being used. The 'jump' test is only for valve and first stage function before entry.

 

[shoredivr]

What is never mentioned in the mad rush to everything electronic is the need for batteries and how many of these that are not rechargeable wind up in landfills. Along with other e-waste. I like to minimize the amount of trash I generate. SPGs for me:

 

[CuzzA]

Fair point, but as you mentioned you can use rechargable batteries and they can be recycled. I don't know how many people do, but I still get paper bags instead of plastic at the grocery store. And the same argument can be used about the rubber hose required of the SPG, so there's that.

Have to agree the watch analogy isn't great. Not because electronic may be more functional, but I can't be caught dead with a cellphone on my wrist. Just like I can't be caught dead with skinny jeans, a flannel tied around my neck in the 100 degree summer wearing a fedora on my head. Not sure what style that is called these days, but it ain't the style of a man who appreciates a fine analog timepiece on his wrist.... Ahh, there I go derailing my own thread. If I offended someone, just carry on.

 

[dmaziuk]

I'm not sure I understand. I monitor the 'needle' (I try to avoid techterminology) over time to see how rapidly it is moving, how rapidly the gas is being used.

That's rate of change aka derivative aka slope, gradient being a synonym for slope.

Do you use different SPGs for different size tanks? The needle will move very differently when breathing down an 80-gallon tank vs a .5 cf pony. You can program the computer to compensate for that.

I am curious as to how they progammed the IP drop (?) NetDoc says his computer detects and warns about.

 

[lowviz]

What is never mentioned in the mad rush to everything electronic is the need for batteries ...//...

Indeed.

And that is the Achilles Heel of my stance and everyone else's who entertains the idea of WAI.

Well done.

 

[CuzzA]

Correct me if I'm wrong, but isn't it advised to service your SPG every year like you would any other piece of equipment. So if the battery (rechargable would be best) lasts for an extremly long time (my experience so far) then the transmitter may not require any more service than what would be required of an SPG. Which would be nothing more than a o ring swap and battery charge/replacement.

 

[undrwater]

Yep. Excellent point.

Agilis, yes I was talking about what a digital 'needle' would need to represent visually the needle jumping during the restriction test.