Why not a button gauge for stage bottles?

[DA Aquamaster]

They do not give you required accuracy. The accuracy of the instrument can be determined by looking at the numbers standing by the notches. The accuracy is usually half a notch. So if you have them standing at 1000psi apart (that what I had on my old button gauge) then the accuracy is 500psi. Not good enough for a deco bottle. You might be reading 1000 psi while in fact the tank has 500 psi.

I agree.

There are two different schools of thought on deco bottles and SPGs:

One school says check it on the surface then don't use an SPG at all - fewest possible failure points and tank pressure is not relavent as you ensure you have at least 1.5 times the gas you plan on using and, since you can't make more underwater and are not making decisions to turn the dive based on pressure, there is no need to know the pressure.

The other school says to configure deco and stage regs for 100% interchangability, and that requires a normal SPG as the button gauge is not accurate enough or easy enough to read.

What that leaves is a thin line in the middle where a button gauge on a deco bottle would serve to give a ballpark pressure check on the surface, and would provide moral support during deco. It is questionable whether some are accurate enough to use as the sole pressure test on the surface (you'd want to confirm it and be very confident before using just the button gauge) and it can potentially be argued that the moral support is just a psychological crutch. On the positive side, it adds very little in terms of additional failure modes and is low profile and light weight, so the harm is arguably slight which tends to help balance the limited benefit.

 

[Mr Carcharodon]

Hello Internets,

I have to rig a couple stages and I was thinking about using a button gauge instead of a short hose and brass/glass gauge...

I had a look around and everyone rigs stage bottles the same way, with the hose a gauge. Isnt this more failure points? Are button gauges crap (never had one)?

Thanks,
C

Probably not very accurate compared to a conventional gauge. And the whole point of the gauge is to know how much you have in there. I suppose if you can tolerate the uncertainty it would be OK, but why have a configuration that only works sometimes.

edit: OK if I read to the end of the thread I would have seen this had already been answered!

 

[akdeepdiver]

I find them useful on my Argon setup. On the small 6cf bottle it works well enough for me to know when to transfer more Argon to it or switch out bottles.

 

[drbill]

I used to use a button gauge on my pony. However, I mount the pony upside down so I can reach the valve easily. Due to some rough exits on the boat's swim step in swell, the button gauge got slammed a few times. Now I use a conventional SPG instead. Of course in your case the button gauge may be fine since it may not get bumped. They are a bit hard to read with my aging eyes.

 

[northernone]

I myself have always used PVC pipe extensions which go a little past the guage face to protect from scratches and also to absorb shock

Scrounged this gem and will apply it tomorrow to what's left of my gauges.

Thanks to you and the archive.

-Cameron

 

[Zaixon]

+1 button gauge on o2 bottle. Just need to tilt the bottle down to read it and not many issues with it. I did drop my reg once and the button gauge stopped working but then I just replaced it with another button.

 

[2airishuman]

I use a button guage and I also need glasses to read, I can't read the old tiny button guages, but the new larger ones are easy for me to read and they obvioulsy eliminate a number of potential failure points, including two O-rings and a spindle that can be snapped off and also a hose crimp and the hose itself.

They are also much less expensive. I got a few from Pirrahana diving and they have worked fine since I got them about 8 months ago. you might be able to buy 3 button guages for the price of a hose and normal guage.

DD has it right. The better quality button gauges are reasonably accurate and easy to read, and are much cheaper than an SPG and hose assembly. I have one from Piranha also, have it on a stage setup, and have good results with it.

I don't dive caves. I use stage bottles two ways. 1) On an extended dive, I'll breath down the stage first then switch to back gas. 2) as a bailout bottle. For both of these situations, the button gauges work fine.

 

[Tassi Devil Diver]

I use button gauges on all my CCR bailout tanks, less failure points.

 

[dumpsterDiver]

DD has it right. The better quality button gauges are reasonably accurate and easy to read, and are much cheaper than an SPG and hose assembly. I have one from Piranha also, have it on a stage setup, and have good results with it.

I don't dive caves. I use stage bottles two ways. 1) On an extended dive, I'll breath down the stage first then switch to back gas. 2) as a bailout bottle. For both of these situations, the button gauges work fine.

I was right (once) 6 years ago... My wife agrees... It has been a tough year at home, but I have high hopes for 2017!

 

[RyanT]

I use button gauges on my stage bottles. As others have mentioned, they are definitely less accurate than a full size gauge. For my stage bottles I don't need the accuracy. I plan my gas to have roughly enough for both my self and my buddy. In a pinch where two of us would be breathing off the same stage, we expect to run short at the end of the deco. We also plan to have some extra back gas available to extend time at our last stop (albeit not ideal). In a normal, no failure dive, I don't worry about checking the button at all after ensuring that the stage is full, because I know I'll have about twice as much as I need to complete the deco. The button gauge is compact and simple and gives me a rough idea of how much is in the tank. If you're doing deco in a cave, I can see where a button gauge would be hard to see. For my open water dives though, it's all I need.