What should the regulator gauge read with a 5lb. cylinder?

I just kegged my first beer and wanted to know what the regulator gauge should read when connecting the dual co2 regulator to a 5lb. cylinder? I purchased a used filled cylinder from NB for my first kegging experience. The gauge first started around 800 and is now just below 600, I am thinking I may have a leak issue? However, I have leak tested and have been unable to track down any culprit.

The other psi gauge has been steady at 12 psi but had a slight increase when placed in my chest freezer, likely from the temperature change.

Thanks!

The high pressure gauge will vary with the temperature. The colder the temperature, the lower the pressure.

And the gauge will read the same until just before the tank is empty.

The gauge reads pressure, not volume. As a standby tank, pick up a 9-12oz paintball tank and adapter. Then if you run out over the weekend you will have enough CO2 to get by until you can get a refill.

http://www.warpig.com/paintball/technic ... /co2pv.gif