SPG questions

[fjpatrum]

I recently bought a computer and console via the scubaboard classifieds. Everything arrived and there were no hoses, which is fine but I've never seen an SPG before that wasn't connected to a hose already.

The SPG has a small tube that can be completely removed and I'm wondering if there are any guidelines about how deep it should be pushed into the gauge etc etc.

So, does anyone have links to point out the various parts of an SPG and how they all work together? How about how one goes about calibrating such devices?

Google and scubaboard searches haven't turned up anything but if there are links available here, I'm glad to read those if you can point them out as well.

 

[tbone1004]

you have the spool which is the metal tube with two orings on it. Just kind of push it in and when you attach the hose it will seat the rest of the way. Some spools have flanges on them but basically it goes into the spg about half way. If the o-rings are bad it's cheaper to just replace the spool because those orings are a b!tch to change. $4 a spool i think.
You can't calibrate spg's. They're sprung and once they go they're pretty much done. If taken care of they can last decades though you just have to be careful when pressurizing it so you don't peg the gauge up too fast.

 

[fjpatrum]

Thanks for the information. I don't think there's anything wrong with this one, I was just wondering. I've seen references to the spool before but I wasn't sure if that was the right name for the part or not. Thanks for clarifying for me. Now I just have to attach this thing to a hose and see how it compares to my old one.

 

[lowviz]

you have the spool which is the metal tube with two orings on it. Just kind of push it in and when you attach the hose it will seat the rest of the way. Some spools have flanges on them but basically it goes into the spg about half way. If the o-rings are bad it's cheaper to just replace the spool because those orings are a b!tch to change. $4 a spool i think.
You can't calibrate spg's. They're sprung and once they go they're pretty much done. If taken care of they can last decades though you just have to be careful when pressurizing it so you don't peg the gauge up too fast.

+1.

While it is still easy and you are thinking about it: take the spool to your LDS and buy a second one for your dive box. Put the spare into a thin cheap plastic sandwich bag, twist all the air out of it, overhand knot, cut close to the knot. -stays clean. (works for port plugs also)