Is the CO2 pressure supposed to drop?

Just put a Dead Ringer in our first keg! Hooked up the CO2 and pressurized to 12psi, put everything in the fridge at 36 F, and left it. A couple hours later the gauge pressure showed less than 10psi. I adjusted the regulator back to 12. A few hours later it was back under 10.

I understand that the beer is absorbing the CO2, but shouldn't the regulator keep the pressure steady? Am I missing something? Is there something wrong with my equipment?

I can't explain the physics of it, but that's exactly what happens to me. Something about the low temperature and its effect on the pressure.

Yes, it should. I assume that when you say you put everything into the fridge you include the gas bottle and regulator. If so the pressure inside the bottle will drop as the CO2 in it cools but the regulator is supposed to regulate and account for that. Also the spring in the regulator will get colder and stiffer but again the change in its behaviour because of that should be small.

The only thing I can think of is that the bottle is almost empty i.e. there is nothing in it but gas at relatively low pressure. The regulator will eventually run out of steam as inlet pressure gets low (as CO3 dissolves in the beer) and you might be able to get secondary pressure back up with a tweak for a short period of time but eventually pressure will get outside the range where the regulator can regulate.

Happens every time.

Glad to know I'm not the only one. The bottle was just filled so it should be good. I guess I'll keep an eye on it and hopefully it will even out.

Thanks for the help!

It should. Eventually the spring (I'm assuming that's whats responsible) will come to thermal equilibrium and it should regulate even though you need to squeeze the spring more. Sounds as if the spring constant decreases rather than increasing which is what I figured would happen.