analog air/nitrox gauge?

[JSpree]

Hey all,

Just a quick one. If I'm looking to just buy an analog air gauge as a backup do I need to buy one that is air/nitrox or does it matter? I've seen some listed as pressure gauges, air gauges and air/nitrox gauges. I definitely dive nitrox when possible.

Thanks.

 

[~ dry]

You mean a submersible pressure gauge (SPG)?

I was taught that all modern ones are nitrox-compatible, at least up to 40% oxygen. My instructors all used the same gauges whether they were diving air or nitrox. And they didn't say that I needed a new gauge in my Nitrox class.

But maybe I'm wrong . . .
Dory

 

[Jax]

What ~ dry said. All gauges work with all recreational stuff.

 

[JahJahwarrior]

General rule of thumb is, no need for any special o2 cleaning for up to 40% nitrox. I'm not sure of a good written source, but I'm sure I've seen it somewhere around here...maybe dealing with the DOT guidelines for compressed gases.

 

[JSpree]

Thanks for the info. I didn't think it mattered but doesn't hurt to ask the question

 

[JahJahwarrior]

If computer companies worked like scuba companies, there would be "Forum Ready LCD monitors" next to the "Email Proof LCD Monitors" with the "Question Asking Keyboards" and the "Troll Ranting Keyboards" below them, all with big fat price tags and sales people to convince you that buying a mouse online could make it stop tracking sooner, or that speakers need to be tested every year and warning you that if you don't run a virus scan every 3 months your warranty will be void...

 

[Jax]

. . . and if architects built buildings like programmers write software, civilization as we know it would be destroyed by the first woodpecker that came along.

 

[Indian Valley Scuba]

Back to the original post, no you don't have to do anything special with consideration to your SPG selection. The key here is that there is no gas flow through a gauge, effectively it is a dead-end in the piping system. Over-simplifying, when you attached your regulator to your tank, the gas in the high pressure hose simply compresses in the gauge innards when the line is pressurized, and remains there throughout your dive, slowly decompressing as the tank pressure falls. Oxygen compatibility has everything to do with friction (caused by gas flow) and contaminants. Take away the friction and there is nothing to worry about.