Button gauges DIR?

[dumpsterDiver]

I have recently been seeing larger and much more legible button guages. I'm starting to try one on a stage bottle. Are these things DIR?

It seems that it will reduce two rubber hose to metal connections, 2 orings in SPG spindle and is more compact. I've used the old ones that were really tiny for years, but my eyes are so bad now, there is no way i can read the tiny guages.

Blue Reef Pony Bottle Tank Small Pressure Gauge from LeisurePro.com

 

[Bismark]

By the looks of that picture, I don't think you could tell if you had 1700 or 1300 psi.........not going to work I don't think. Need to be more accurate than that to calculate gas I believe.

 

[cfenton]

I have recently been seeing larger and much more legible button guages. I'm starting to try one on a stage bottle. Are these things DIR? [/url]

No: Not accurate, more susceptible to damage, hard to read.

http://www.scubaboard.com/forums/dir/215172-button-gauge.html

 

[TSandM]

What worries me in looking at the ad is that there are no dimensions on the gauge. If you took a sufficiently close photograph of the one I have on my argon bottle (when it was new, and clearer) it could look like that. But in practice, the face is far harder to read than that photograph would imply.

I don't do decompression diving, but don't you generally plan a rather generous oversupply, in the event of lost deco gas? I don't think detecting the difference between 1300 and 1500 psi would be a big thing. But not being able to read the gauge easily could be.

 

[cfenton]

I don't do decompression diving, but don't you generally plan a rather generous oversupply, in the event of lost deco gas? I don't think detecting the difference between 1300 and 1500 psi would be a big thing. But not being able to read the gauge easily could be.

Reserve for lost deco gas are generally backgas. It doesn't help to have an oversupply of deco gas if you lose the gas.

IMHO being able to tell the difference between 1300 and 1700 is useful. And regular spgs aren't overly accurate as it is. I've been on many dives where I'm breathing a stage for several minutes that is reading 0 psi.

 

[Bismark]

What worries me in looking at the ad is that there are no dimensions on the gauge. If you took a sufficiently close photograph of the one I have on my argon bottle (when it was new, and clearer) it could look like that. But in practice, the face is far harder to read than that photograph would imply.

I don't do decompression diving, but don't you generally plan a rather generous oversupply, in the event of lost deco gas? I don't think detecting the difference between 1300 and 1500 psi would be a big thing. But not being able to read the gauge easily could be.

Not to beat a dead horse but I believe I wrote 1300 and 1700. Also, I am not a cave diver but how would you feel calculating thirds with gauges that were that accurate?

 

[Bismark]

What worries me in looking at the ad is that there are no dimensions on the gauge. If you took a sufficiently close photograph of the one I have on my argon bottle (when it was new, and clearer) it could look like that. But in practice, the face is far harder to read than that photograph would imply.

I don't do decompression diving, but don't you generally plan a rather generous oversupply, in the event of lost deco gas? I don't think detecting the difference between 1300 and 1500 psi would be a big thing. But not being able to read the gauge easily could be.

Also Lynne, your reserves of deco gas are intended for your team mate(s) and vice versa if things go wrong. This is not padded excessively. I believe that starting a dive with an SPG that was as much as 400 psi out of whack would violate the principle of not diving with knowingly broken pieces of kit. One thing goes wrong, then another, and pretty soon you are half way down the incident pit.

 

[dumpsterDiver]

OK OK I'm a liar. I put it on my dreaded pony bottle (not stage bottle) that is back mounted and therefore I can't read it underwater. I basically need to know the pressure plus of minus 3-400 lbs before and after each dive. If someone doesn't have some (good) reasons not to, I'm going to use them on my Oxygen reg also.

The guage is quite legible to me, and I can't read without glasses anymore.

Sorry I did not see the old posts for some reason.

 

[DA Aquamaster]

SPG's are usually most accurate in the center of their range. Gauges that read more than zero when unpressurized never leave the factory, but gauges that may read "0" when they still have 100-200 psi are pretty common and not viewed as being problematic as they are more conservative.

Not all button gauges are created equally. The old ones were small and very hard to read - even on the surface. The newer ones are much larger and come in two flavors - one with about 120 degrees of needle movement and one with 180 degrees.

All that said, on a stage I prefer a very accurate conventional SPG on a 6" or 7" hose since the turn pressure matters and accuracy and discrimination count.

On a deco bottle, I'd argue you don't need one at all. You check the pressure pre-dive, ensure you have at least 1.5 times what you need for the dive and then you have what you have. You can't make more during the dive so there is no real value in having a gauge.

In that regard it can be argued that a gauge just adds failure points. On the other hand if you feel you have to have one on a deco bottle, it makes more sense to have a button gauge. It adds only a one bourdon tube in a fairly tough brass body over the o-ring and plug you have already and is much simpler than the o-ring hose, and HP swivel and bourdon tube used with the larger brass and glass gauge.

 

[Bismark]

Dumpster Dive, if the reasons posted above are not "good" in your view, I don't think Chris and I are going to lose any sleep over it. Neither of us are scuba cops so have fun. Not trying to be impolite but you did post in the DIR forum, so don't be surprised you got some DIR answers.