Originally Posted by bruin_ale
Yes, putting your tank in the fridge causes the pressure to drop inside the tank gives your high pressure gauge an inaccurate reading. There's nothing wrong with your regulator, that's normal.
Well, if your fridge is at -78C it might read zero, otherwise it'll drop to somewhere in the 400-600 PSI range when refrigerated. If it's not reading something over 400 there's something wrong with the gauge. The gauge should always give you an accurate reading. It's just that they'll be less pressure in the tank at lower temperatures. You'll have the same amount of liquid CO2 (by weight), but at a lower pressure.